i dunno if u got the answer to ur question yet but i have made my own spray booth so i can help you out.
all i did was go to the warehouse of the local appliance distributor and asked them for a refridgerator box.
In my shop (my garage!) what i do when paning is hang the bodies from a wire hanger that I turned into a kind of hook, its almost like a butcher shop lol. Anyway i had probs with paint dust getting everywhere, so what I did was put a tarp down, then i cut the fridge box open on 1 seem and cut a slot in the top of it so i could accomidate for the hanger to fit thru. then i just position the box around the body.
when i need to get the back of the body all i do is turn the box. it's pretty simple and seems like a poor mans method but it's usually the simplest ideas that work the best. i hope this helps.
JimBONES!