You could actually just use a small tire.
Inflate it with your pump, then hook up your airbrush hose up to it.
I personally use a 5 Gallon Porter Cable, when I want to use it I flick the switch until its charged up, then turn it off to avoid the startle of unexpected startup.
It has a built in regulator, and a quick coupler for my 1/4" - 1/8" Hose.
Works like a charm, and it only cost me $45 at the swap meet.