Hi there.
I am by no means an expert, very new back into modelling myself. I have however done quite a bit of research on airbrushes lately.
What I have gleened from these forums, is that there are two camps. The Iwata camp, and the Badger camp. While they do socialize, the only thing they really agree upon is the Aztec (Testors) are to be avoided. These are generalities, and there are some who are very happy with thier Aztecs.
One option that is not often covered because of availabilty over here is Aerograph / Devilbiss. Everything I have read leads me to believe these are fine tools, just not very available nor servicable on this side of the pond.
On Ebay there are several Aerograph's up for auction at this very moment. Most of them being sold from the UK (better on shipping for you).
As for compressors, all I know is that you should have a moisture trap in your line. Not much help there I'm affraid.
I am sure your there are many hear that can be more helpful, but I just wanted to share my 2c.
Happy modelling
Yolev.