More research and more design. Finally I've been able to move forward again. I screwed 1x2's into the ceiling of the garage to give me something to tape/staple plastic sheeting to the ceiling. the bottom drapes the floor about 12" giving me a good seal, I'll probably lay scrap lumber on the edges to hold everything down. I built a frame near the A/C to allow a large furnace filter to be stapled and sealed with duct tape to allow only filtered air into the booth.
I basically worked the walls around all four of my lights to make sure I'd have plenty of light.
