You need to get that buldawg dude in here and look at it.
The build looks great to me but I would think about how far your heat has to travel before it gets to the meat. In a UDS the basket sits right below the meat and in your set up it has to go up a 55 gallon drum then over into the cooking chamber. It seems to me your fire has to work twice as hard. IMHO you have to look at it like a traditional offset smoker.