Need a new air compressor

First three rules of compressor selection for blasting-

1- CFM

2- CFM

3- CFM

(*4) psi and gallon capacity mean almost nothing as you will exhaust the tank almost instantly unless you have 50 CFM

You are right about 12 @90 being about the minimum for any semi-serious blasting.

My 1980's Bel-Air model 318 (was originally a 338 converted to 220 from 3 phase with factory parts) keeps up great with my medium sized cabinet.

As long as you're above that 15-20 @90 I don't think you can go wrong with Quincy, Bel-Air, Speed-Aire, even IR for Mid-level equipment.