Air compressors have only 3 things to worry about.
CFM output.
reciever tank size.
engine running it.

Bigger is always better in all three in the long run.
get the biggest of everything that you can afford.

The chinese made compressors that are made now are fine for a backyarder. I have had a 17CFM "Blackcat" (cheap chinese unit) for nearly 4 years now, and it goes like a trooper. Even the cheap compressors come with regulators so that you can adjust the flow and pressure that is being output. A larger compressor can be wound down, but a small one cant be wound up.

A bigger reciever tank means that the compressor doesent have to run as often to deliver tha same amount of air.

The engine to drive the unit is determined by what power capacity you have (10 or 15amp) or 415v if you are lucky. Petrol engines can be lound but a cheap method of getting a large CFM unit.