I'd have to do some serious digging to find pictures I know I have, but for my "medium" spray booth setup, I use an old key-slot style shelving unit I have and no longer use.  Compact and out of the way, and easy to set up when I need it.  I just use 6-mil plastic around the outside to keep its structure, and 2 old shelf boards across the top as a sturdy top to set things on and hang things from as needed.  My big setup is an 8x8 instant canopy with 6-mil poly around the sides and a painters drop cloth on the floor.  Exhaust filter intake goes in the booth and exhausts outside, and just draws air through like you talk about Will.  

I do effectively the same thing with my shop-made diode laser enclosure too, some intake space in the top and an exhaust fan that goes through the garage door.  

MosquitoMade.com