Witt,
I have two Aztecs, 1 Paache, and 1 Thayer & Chandler.
I would advise to go with something like the Testors Aztec airbrushes.
They are far from the best, but they has the most available outlets and replacement spray nozzles are inexpensive and readily available. All are dual-action and relatively easy to use.
The real trick when using an airbrush is getting the paint properly thinned, enamels have more leeway than acrylics. You will probably tire of that little Testors compressor, I have never like any compressors, they often give uneven airflow, need water traps, and are noisy. I use compressed Nitrogen, but compressed CO² is just as good. Both are better than compressed air as both are very dry and will not condense, so no moisture filters are required. And a compressed tank with a good regulator will give even press with nothing but a slight hiss, no compressor noise.
Always clean any airbrush good after each session, one of the chief casualties for early airbrush users are clogged needle valbes and tips.
Learn small, get some artboard and have a spray fest. Learn how to use a dual-control airbrush that allow one to control both airflow and paint flow. Write your name, do some circle, just familierize your self with the airbrush, because it is a tottaly new medium from brushes. Once can do marvels with an airbrush, they will shoot anything for lacquers to inks. But as I said thin properly.
A good rule of thumb is to get your paint thinned to the consistance of milk. I always stir my paint when thinning and slide my stirring stick up the sides of the paint cup. If the paint flows back transluscent, it is too thin. if the paint slide back slow, it is too think. if it slides back even and opaque, you're there. Even when thinned properly, learn the proper distance to shoot for best results; too close and you're likely to get runs, too far back and the paint will semi-dry before it hits the medium and be powdery.
It is not a long curve, but like anything else, you cannot win if you do not play, so practice, practice, practice, No book is ever going to teach you how to use an airbrush like good old first-hand experience and learning mistakes by the old-school method.
Shoot away Witt, if you built plastic models, you will wonder how in the world you ever did with out and airbrush.
Caz