Check Home Depot. It will be in the cement section. 2'x8' piece for about $9. It isn't heavy gauge, but it's easy to work with and big enough to make a few coal holders.
Am I tough? Am I strong? Am I hard-core? Absolutely.
Did I whimper with pathetic delight when I sank my teeth into my first brisket? You betcha.
Chargriller Pro w/SFB 3 generic digital thermometers