I use one of the office type lamps that is essentially two long arms with springs to hold tension (Wally World- less than ten bucks). It sits in a base that I permanently mounted to the top of the unit and has a single pivot point. That way I can swing it around from the shelf table to the chamber and pull it down to rack level for food viewing. I also like it because it will pop out of the base for storage in the cooking chamber between smokes.
And I second or third or fourth the other guys in that any good enamel paint will suffice for the outer skin. Just rough up the surface a bit with a green Scotchbrite pad and spray bomb away.
I have to say that I love a big chamber smoker- of any kind. It does make one feel like a bad *** when opening a huge "vault" door or the like and having the smoke roll out in yer face. Oh, and there's just no limit as to what you can smoke or how much of it you can do at a time. Wanna do a whole side of beef? Yeah, go ahead! How about a small pig? Do it man! Got a whole tuna? Hang that bad boy right in there! Smoke on!!!!
Jeeze, I'm gettin off just writing this!