I've got a bigggg compressor that has to be regulated down to 90 psi too. Waiting for two weeks for the little guys / pancake style to air up is pointless. If you're going to do a lot of blasting, an inline dessicant filter of some sort is a great investment and pays off just in nozzle cleaning time.
I have to agree with both of your statements there YY1. I've got a 50 lb. pot blaster and it's more of a pain than it's worth most of the time. I've never had issues with the valves clogging up -- I use fine grit -- but that big dog will go through 6 cubic feet of media in a minute so it eats up a lot of time in refills and straining the media on the tarp. (Ya'll can see now why I love my 5-foot blast cabinet so much LOL :-D) Since you're considering one twice that size my5thmopar, the output rating might help you figure out approximately how much media you'll need but until you get the setup up and running it's probably tough to estimate.
Brass ball valves last longer than what comes with the HF cabinet. You can pick up consumables at a good price (and a nice gun upgrade kit if you're inclined) from TPTools.com.
