If you have a service station with free air nearby, you may want to consider going for an actual air tank rather than a compressor. You could probably get a 10 gallon for fairly cheap. And on the plus side, when you get an actual compressor you can just fill up your big tank with it (make sure you don't overheat your compressor though).
http://www.airbrush.com/forums/tm.aspx?m=88561
You'd still need the adaptor, regulator, filter, etc., though.
Nathaniel