Brad:
Having the same problem here. LIke you I don't want to buy too cheap and then upgrade later.
I'm looking at the Badger 175 and the 360. Now I just saw an add in FSM for Aztec.
Badger looks good, fine lines down to pencil width and spray up to 2.5 inches.
The 360 takes care of all patterns with one needle and nozzle. The 175 you have to change needles and nozzles. Seems time consuming.
The Aztec seems interesting, no needles to change, just pop on and off a nozzles as needed. That seems convenient. But some of the web sites don't give a whole lot of info what type of paint or abilities the burshes have.
Now the Badger site is pretty good. There is much info on the products.
Testors, for Aztec, not a whole lot of info.
Two retailers I found from this forum are ,Coast Air Brush http://www.coastairbrush.com/toc.html and Dixie Art http://www.dixieart.com/FineArts/FineArtMain.html
Going to do some searching on the form
Matt