Exactly what I wanted to know. Right now I have a modified Charbroil Vertical water smoker.
I have added a digital temp control from left over industrial parts (the stock unit dosen't have temp control), and put the whole thing in a 2" thick styro box, but is a pain to access, and leaks smoke like a seive. Time to get something new.
I've thought of building somethine like a cookshack, but with the price of SS and my lack of time, I think I'm better off buying one.
For those of you who are building smokers, I highly recomend a digital temp controller. My smoker will hold +/- 3 Deg F. You can pick them up on E-bay for around $50 course you'll also need a heating element and a thermocouple.