DO NOT buy a single action airbrush.
Get a dual action gravity feed model.
The Iwata Revolution CR is about as good an airbrush as you can buy for modeling. It is also very affordable. Try shopping at an art supply site instead of a hobby site. I have purchased airbrushes from both
Chicago Airbrush and from
Dixie Art- I can recommend both. They are also great places to shop for compressors, and they may offer you free shipping.
Tamiya rebrands Iwata airbrushes. Having used both, I prefer and recommend the Iwata.