The good news is that blast cabinets are pretty simple. I've had a cheap HF one and now a really nice Trinco. They both took air from my compressor, sucked up media, and blasted it at the object. There are really no moving parts, although the Trinco has a dust collector. Both units tend to cloud up the viewing window with a few hours' use, which is really the only real pain. Just get replaceable films to put over the inside of the window.
If you're into modding and your parts aren't large, my very first blast cabinet was a big Rubbermaid tub, a $20 HF gun, $10 HF blasting gloves, and a piece of glass glued to a window cut out of the cover. I even plumbed in my shop vac hose for a dust collector!