My next wood project is building a vertical wooden smoker. I'm going to use a propane burner for heat and a mailbox on the side to put my AMPS smoker in. I'm going to double layer all my walls with insulation. Going to wrap the inside with aluminum. My question is what is the thinnest metal I can get away with using? I'd like to work with something I can easily bend and shape and more importantly cut with cheapo tin snips. Haven't done much work with metal before so I'm flying blind as far as that goes. Thanks in advance.