I am thinking I will be going with steel. DesertDweller brought up the right idea and I agree. The steel will; A) hold up better and B) retain the heat better.
I figure I will use plates that are about 1/16" - 1/8" thick.
Countyliner or Que: I do not even have mine yet....I want to get all materials prior to assembly.....what lenght will the plates need to be?