Just a quick note here. I called Miller foam, the first contact on the list that "weekend plinker" listed (Thanks for that) and I talked to a guy named John.
He suggested "Extra Firm High Density Polyurathane (sp) Foam". It comes in dark charcoa, is chemical resistant, comes in many different thicknesses up to 2" thick. Sheets are 24" by 72" 2" thick are $36.00, 1" thick sheets are $18.00.
They are in South El Monte.
I am in the process of building a foam cutter, just in the begining stages of tracking things down. I'll keep you all posted on how things go. Heading out right now to get the Nichromium wire.
A big thanks to Elwood Blues for posting his projects, information, and wiring diagram.