I am going to have to see pics to understand what you are doing. You say it is going to be 2x2x3. Is your smoker already 2x2x3 or are you going to make this box to add to your existing smoker? When you say your going to line your smoker does that mean the bottom rusted out on you and you got to reline the damage? You see what I mean? It is confusing.
I took a cheap char-broil,added a hotplate to it(1000) watts-works well with space blanket around it-bro uses old sleeping bag with space blnkt. around his-doing bbb&is up to 150 tonite in San Anton.-says cold tonite-but in his shop.really been working tonite to post pics-spose I have to wait for allie to help me.she better than me at this stuff!