i made mine and i am glad I did.
i used a 6x10 air conditioning duct part and hot glued the fans in. yes, the fans are intrinsically safe.
the bottom of the booth is slanted to the fans. i used duct sheet metal for that. some green cut to size filter catches all the overspray and i use the grate off a screen door as a floor. as seen in this pic
the duct was less than 30 bucks. the light and grate was like 40 and the fans were free
the out side can be made with painted plywood or what ever. if you cant find or just dont trust brushless fans then ebay
jenn-air fan.
these suck in a good way. for around 50-75 bucks you cant lose. for 120-150 bucks, you can build a way better booth than can be bought.