I concur that the dual action gravity fed internal mix airbrush with a medium needle is the most versatile airbrush. I own single action siphon fed, dual action siphon fed and dual action gravity fed airbrushes, and it's the latter that I pull out of the holster most. Easy to use, easy to clean and slightly less wasteful of paint (no siphon tube to clean). My personal choice is Badger (200-20, 150 & 100LG), but most of the "brand" name airbrushes are excellent tools.
Given your location give Bear Air a call. Their located in S. Easton MA, a short drive away if my geography is correct. I'm not sure if they have a store front, but if they do it would be worth your time to visit to handle the different kinds of airbrushes they offer.
A decent starter combo compressor/airbrush is their Polar Bear 1000 & Peak C-3 for $125 + S&H (you might be able to save on the S&H part!). Recently a fellow FSMer (Zokissima) bought their Polar Bear 2000 & Peak C-5 for $219 + S&H, and has expressed satisfaction with his purchase. You would have to buy an airhose (around $10), but they do come with regulator and moisture trap, both very important for successful airbrushing!
There are better compressors and airbrushes out there, but I'm loathe to suggest a beginner to buy a $250 airbrush and $500 compressor.