I found another commercial freezer and it is stainless on the outside and aluminum on the inside. Before I call the guy to say I want to get it from him, I want to make sure Aluminum can be used with the heat.
I would say if you have a fire hot enough to hurt aluminum you ain't going Low N Slow. Aluminum melt point is 1220Âº F. I would say that there is insulation between the two layers... so it should hold the heat fine and work well for you... my opinion though
Actually aluninum and copper give an even heat, that is why it is used on the bottom of the better pots & pans that are made of stainless steel. Stainless is a poor conductor (read hot spots)
Hope that helps.
My .02 worth, folks put their wood chips in foil and throw them on the coals, heating element, or gas fire and have no problems. People also make pouches to cook in on grills and open fires, no problems. Just make a rack to keep the heat source a few inches from the aluminum on the sides and bottom and you shouldn't have any problems. With good air movement in the smoker I can't forsee any problems at even say 350*