I've heard that the fans in range hoods were good choices...after all, they are designed to pull smoke- and grease-laden air. However, I'm no authority on the subject.
Here's mine:

This is an unfinished, pre-built cabinet from Home Depot ($55, maybe less if you can find a damaged one). I added a top (plywood) and a couple small bar lights ($10 each I think). Ventilation is a 12-gal Shop Vac (extra hose, $10 or $15) that vents outside.
The lights aren't perfect, I'll need brighter ones now that I'm starting to get the hang of my airbrush. But it works great, and I can use the Shop Vac for "normal" duties if necessary. Plus I didn't have to rig anything special up for it - i'm no electrician. Periodically I re-paint the insides white for better visibility.