Going to build a smokehouse?

I am going to build a smokehouse this week to smoke sausage that I am going to make this weekend. I am in need of some advice. My plan is to build it from wood and use a propane burner. I typically use our old smokehouse at the hunting shack but I have always wanted to build one at home so I can do all of my processing in one place. I plan on 2x2 framing with 2x8 pine finishing the inside and plywood on the outside. My main questions are should I insulate it? If I do what should I use? I also want to put it in my yard and I would like to side it like my house (which is vinyl). Will the smoker put off enough heat on the outside to melt my siding? Most of my smoking temperature is around 200 degrees give or take. Also what is the best bang for the buck on a burner and where do I look for one.