I reckon you need to buy the biggest compressor you can afford or can run on your single phase power, unless of course you have 3 phase in which case go bigger still LOL
Sandblasters work by essentially using compressed air to firstly suck up sand in a venturi affect then blast it onto your work at a fast pace, the more air you have available to do this will result in a better faster job,
which ever cabinet you get will specify a required amount, aim for that plus say 15 to 20% as a buffer and ya should be all good
