check out craigslist or a local buy and sell for a pot. You will find a used one no problem for cheap. put a ad on if not. Tons of guys have bought them and now they sit. I get offered free ones all the time.

Stanton. undercoating is no problem for me with glass. its just nice if the customers scrapes some of it off first but I can get it no problem.

coarse media (anything under 50 grit). you will use more than a fine grit. finer media does a cleaner job without leaving paint and residue behind and leaves a nicer profile on the metal. I like 50-100 grit for most of my jobs. I use 100-200 on vette stuff and really tender projects.