I looked into this a year ago. Much must have changed in terms of options but a lot of it is basic. A few words:
1. There are two Specs/standards of lights: EURO spec. That is the superior performer hands down and without question. That is the light you find in MB and BMW and Porsche. It is the spec that drives how well and in what shape the beam is focused. These are the lights that you see with the distinct line of dark and light across the car in front"s trunk. "The dark part" is what the on coming driver sees as a car coming at him with very dim lights though clearly visible. ALL the light is focused in the usable area so maybe twice as much light is usable and benefiting you. What would you want with light in the trees or even above 4 feet? EURO SPEC simply "must" be legal....so many of the imports have them?
SAE is our spec and I don't think it is legal anywhere in the world except here and Kanuck and only there cause they tolerate us. Avoid this, if you can, even if you have to fudge a little.
Bulb size. You can get bulbs of any wattage you wish. Some will get you arrested the very first time you turn them on even in daylight. It is THAT obvious to a cop....and thank God. You can bump you bulb wattage a few watts and get some benefit and it won't be obvious IF you are using Euro Spec hardware and it is properly aimed.
When you measure "the voltage" for the headlight you MUST get the voltmeter "across" the bulb and that means your voltmeter leads must be connected to each side of the bulb at or near the bulb. It is only in a perfect world that you can put one lead on the bulb and connect the other lead to the frame. And if your world were in fact perfect you wouldn't testing anything. They make test leads that have a needle thingy in the lead so you can "pierce the wire you want to measure....really handy and not expensive. If you are measuring 12 volts or so.....you have a grounding/supply problem. If you go back to the battery you will see 12.6VDC. If your bulb only shows 11.6v you are down a volt and that is what logic would say is a little less than 10%. Ain't so, Mary Jane. The light output is non linear and the last volt gets you way more light output than the seeming percentage. Not a single vehicle that I have owned in the past 20 years has not ended up with cube relays wired into the headlight circuit so I got full bat/charge voltage at the bulb and I didn't do that for amusement. The OEM relays, switches and all those connections sap voltage drop/current from the system. Let there be light. Use the standard system that is currently running the bulb as the "signal" for the relay so your OEM system is still intact but running along side the "new power source". The cubes are rated for 30 amps and the standard headlight stuff is 15 or 20 amps. Never had to replace one.
Never ever buy "sealed beam" headlights. The only ones that I ever even saw that were up to snuff were a set of Hellas that had the exact same lens that my "non sealed" Euro spec had but also had the little bumps to allow aiming. The optics must have been spot on but I change out my Halogen bulbs when they get that darkened coating inside the bulb glass. 14.5 Volts will push their performance to the design level and they don't last as long as in a system running them at 11 volts. Every other year but I run with them on in daylight.
Bulb "temperature" is the wave length of the light that is emitted. In clear dry weather those Euros with that brilliant blue white bulb seems to shine further and brighter down the road. Problem is that in rain or even wet conditions that same bulb becomes inferior. In fog it is decidedly dangerous unless precisely focused....and even then. There is a compromise temp that works marginally in fog and really good in clear. It isn't that brilliant one but is especially bright Xenon. I think you can select temp in Halogen also. A good Halogen is all you need....ever.
Light shape does matter. The best and easiest is the 7 inch round. Long the standard. But most can be had in a superior performing size. EXCEPT, those little square ones, quads. Those are a waste of time regardless and you can spend a lot of cash learning that. The be all end all for low beams is currently the "projector" light. Razor sharp cut off and precision focus in some models. You can get there more cheaply. In fogs the little square shape seems to perform well cause the fog is focus differently than a all purpose light. I have only the square ones but the absolute finest performers were a set of 6 volt 7 inch rounds I had years ago.
Fogs. There is only one real color for fogs and that is my personal opinion. Those little square fogs that are OEM and are "white" are worthless. You think you can see thru fog with those puppies you are delusional or never had a amber pair. Those bright "yellow" items are better than white but are inferior to dark amber although the bright yellow items are really "pretty". You will have to look for amber cause it is not recognized as the "one and only " anymore. Worth the search. If you already own the white ones look for a replacement lens in amber or yellow. If neither of those are available you can buy "BULBS" that shine yellow and they are not that spendy. Amber cuts down on the light that gets transmitted thru the lens so you might consider getting bulbs with a higher wattage cause, while still illegal, you are putting out the same amt of visible light. Over heard at the side of the road " you see officer, I am really only.....".
The best source of information on lighting is a guy named "Daniel Sterns". He likes Pilot and Cibie but sells other brands. He doesn't like Hella. I have six Hella lights on three vehicles and have used them for the past 15+ years and am delighted but I don't knows everything or even close but this proves to me that there is a chance he can be wrong. But not much of a chance. Even if you don't buy from him find out what the Mfr is for the replacement bulbs for brakes and backup and equip all your rolling stock with those. I am really impressed with that. He doesn't seem to want to provide those and take a markup, which I would gladly pay him, but just passes the info. Can't beat that deal.
You should be able to get Euro spec for just about everything, cars and all, from Canada. Sterns gets them and sells to US customers even though that used to be illegal. All the US cars that are sold in Europe have ES lights and they are worth going for.
Most hi beams have no side illumination to pick up the deer and bicycles. Using all four positions on a quad for hi beams would improve the reach but leave you exposed. Hella makes a small light that is called the ALB for aux low beam. It is a superb pattern....low flat and with a serious up sweep to the right to spot the deer. The exact same patter as on my 7 inchers and worth every penny if you don't have that performance already. I have it twice.
I like your comment about "over driving" you r lights. I have a Lexus SC 400 for my distance work with Wifey. Absolutely GREAT driving car and set up for rather hi speed cruising. Engine is governed at 144 MPH and my tires are spec ed for 150 mph to be on the safe side. (joke there) Superb lighting system. I have projector low beams that put all the legal 55 watts where it should be and the high beams play with the lows when they are turned on. Four lights and they cover all the angles or areas of interest. In traveling eastern Or and Idaho I prefer to drive at night to make better time and given the lack of any traffic, the quality of the lights and the serious brake up grades I have made I feel comfy cruising at 100 mph in the flats and open desert. One night i was scooting along with the cruise at 100, a glass of red in one hand and a joint in the other and the Grateful Dead blasting on the Nakamichi and I took a slow curve at speed. I WAS KIDDING about the Red and the Joint...yesssh, what grumps. As I came out of what could only be technically referred to as a curve, I spotted 10 (at least) deer "grazing" in the middle of that lonesome Black Top road. My lights reach out a quarter mile plus straight down the road but in a curve....not so much. I estimate I had maybe a 50 yard glimpse and was closing rapido. I stood on those ABS wonders and the car filled with a loud and rapid DAH DAH DAH DAH. While my heart was competing with that sound it turns out it was the ABS switching the wheels on and off. The car stayed straight and true....aimed at this enormous friggen BUCK that was staring at me ...coldly. Did you know that you can actually change the direction of a car with the brakes jammed on and not loose control? I though so many things and discovered so many things that clear brisk evening at 2 am. All those friggen deer were standing still. All those friggen deer were looking straight at me. All those friggen deer were headed in different directions. They freggin looked like they were friggen set up for friggen grazing in the middle of the friggen road. I used the word friggen a lot that night. Well there was only one path that went thru the heard without hitting at least one of those critters and I only needed to adjust about 5 feet to the center line. The huge buck was on my right heading towards the center and a doe was heading at me on my left. I went thru the gap at a leasurely 80 MPH with the brakes thumping and, I have to admit, I pooed a little. Ever seen that famous masterpiece called "the Scream". I modeled it. The nice thing about hitting a big buck at that speed is that, his being tall, you go under him and don't mess up the front of the car as bad as when you hit a doe. Been there and done that. Then the next day bought my first set of Hellas for that truck. The Lex does not need more light....it needs to not be overdriven in a curve. Really good lights can lead to over confidence. But that was in the good old days....I am older by 4 years now and wiser.
Good luck with your lighting adventure Cody and all,