Metal tool box smoker

[joecoll911]

I've recently came into possession of a big metal tool box (5x3x4'). Looking to make a smoker out of it.

Questions;

Should I worry about the existing paint on the inside?
Should I consider insulation? If so, what kind?
What kind of heat source to get temps high enough to get product up to safe temperature?

 

[daveomak]

I've recently came into possession of a big metal tool box (5x3x4'). Looking to make a smoker out of it.

Questions;

Should I worry about the existing paint on the inside? Yes... I would sand blast the finish so as to not warp the box....
Should I consider insulation? If so, what kind? If you do, you will have to build a second skin on the smoker... rock wool boards or fiberglass boards... 
What kind of heat source to get temps high enough to get product up to safe temperature? Gas or wood would work...