I use a Campbell Hausfeld compressor, I purchased from my local WalMart. It's a 2 gallon compressor with a built-in regulator and 100 PSI max. I purchased the CH moisture trap and mounted it directly to the compressor side. You do need a moisture trap because all compressed air will have water form in it. This will work it's way into the airbrush, mixing with your paint and onto the model. The trap also collects dust particles and such.
I have been using it for a few months now with no problems (using with an Aztech 470 airbrush) The one and only complaint is that it IS a bit noisy. I paint in the garage so, it really isn't a big issue. I don't get a cut in pressure, when the motor kicks on, to start refilling the tank either (this is an issue with some compressors) Some will drop pressure in the middle of painting and make the airbrush tend to "spatter" the paint instead of spraying it.
My airbrush also came with an adapter so I had no problem with connections. For the price, I couldn't beat it. $89.00 for the compressor, $10.00 for the moisture trap. Plug it in, turn it on, close the valve to fill the tank, connect your airbrush, set the PSI for the airbrush (I use between 21-28 for my Aztech) and spray away. No maintenance.