Sean, Can you suggest an item number for a solenoid from Grainer. I have an account with Grainger which happens to be quite close to my home.
Sure. I would use this one:http://www.grainger.com/Grainger/items/6C025
This is a White-Rodgers contactor with a 24-volt coil. It is rated for 200 amps continuous, and 600 amps "inrush" -- hard to tell from the Grainger page, but clear in the White-Rodgers catalog, here:http://www.whiterodgers.com/wrdhom/pdfs/06_Cat_pages/Cat_06_pg0120.pdf
or the spec sheet:http://www.whiterodgers.com/wrdhom/pdfs/sell_sheets/R-4005web.pdf
As I wrote earlier, you will seldom, if ever, see currents higher than 200 amps, and then only for a few seconds. The rating on this contactor should be more than adequate -- it's rated for 50,000 cycles breaking 200 amps.