I looked at the pictures in your gallery; that booth looks really nice. It's too bad it didn't work out too well. I've had fairly good results with a booth made in the garage. As you noted the main problem is getting enough light. I keep getting more lights but it still isn't enough. I think I'm going to have to go all out and buy a bunch of flourescent light tubes and mount them on the walls and ceiling.
The worst problem with mine is that I leave part of the door open for the exhaust. This works fine until evening and the bugs are attracted to the light. A few days ago I had a beautiful coat of clear ruined by a little fly. DOH! Now I'm going to filter the exhaust too so that nothing can get in.
Anyway, good luck with your next booth.
81 Grand Prix, 355, 700r4, 8.5" 4.10
64 Oldsmobile Jetstar, all original