I agree, BearAir is a good place to check when you are ready to buy.
I have owned and used Paache, Badger, and Iwata (unfortunately BearAir no longer carries Iwata airbrushes). I prefer double action airbrushes, as they give a bit more control. If possible, find somewhere to try some airbrushes before you make a purchase.
Here is a site that may help you in your search.
www.howtoairbrush.com
Hope it helps.