Ok.. I have gone the direction most of you have recommended which is a cabinet smoker. In this specific diagram I have added something I would love to have.. I would like the middle brace for the rack holders to be removable. In this case racks that are 4.5' or 5' across and 4.5' deep are too unmanageable for one person, so racks of around 2.5' wide and 4.5' deep sound much better. BUT.. in the case where I want to do whole hog.. or that cut of meat that tips the Flinstone's car over, I can have 1 or two 4.5'x4.5' racks to slide in. Would probably be something I do only a couple of times a year but while I am building it, thought I might get people's opinions.
As far as the drainage, I have not figured that part out, just wanted to throw this out there and see what people think.
One measurement that is not in the pics is smoke stack height which is 24 inches. I think that is using an online calculator so I don't know if I have that one correct.