Thanks for 100 ideas on what to do and not do. I am in the process of steel framing, and then skinning with 1/2" durock all around. On top of that, I was hoping to do a combo of stone and cedar. Stone on the outside face, and cedar on the inside. I know I want non-combustible materials for my box, but would wrapping it in cedar cause me any undue fire hazards, besides the obvious that wood is indeed flammable. The cedar would be directly around the front of the base of my Napoleon 30" head unit.
Sketchup and current progress as follows: