When it comes to compressors, bigger is (almost?) always better. Opinions will differ on size, but here's what I was recommended by a pro for a home painting setup: 16 - 20 cfm (i.e 450 - 570 lpm) free air delivery. I haven't priced one yet, but that's 2 or 3 time bigger than your usual $200 SCA special, and I fully expect that it would have sufficient capacity to run a sandblaster too.
Like carburetted turbo engines, sandblasters can come as draw through or blow through (i.e. pressurised), and although I've only just started looking at them, I think the latter is more efficient.