Long time no see or talk. Clad to hear that yer shop is almost ready. (ours is a huge mess, but we're operating out of it and organizing a little at a time as we go)
Now for the parts parts washer I used to use a mixture of gas/diesel or just kerosene.
Now I use "brake & parts cleaner".
I used to buy brake cleaner in cans by the case (several cases a week!), but then last summer I was turned on to a source of it in bulk. So for less than 10 cases I bought a 55 gallon drum, for another $25 I bought a quart sprayer jug that you fill with cleaner and use the shop air to pressurize and spray away!
So for less than I used to spend a month on "cleaner" I bought 55 gallons and still have 1/2 of it left a year later! (if you get by this way we can hook you up with 5/10 gallons pretty reasonable!)
Of course as Clifford and many others say kero, diesel, or gas work pretty good, but the insurance companies frown on improper storage of those.