Seth --
I've been using airbrushes for nearly 40 years. I would STRONGLY recommend you avoid the inexpensive (cheap) airbrushes that are available. I would also be very leery of any brushes found on eBay unless you can really trust the dealer, like Nate (Sushob). There are so many things that can be wrong with an airbrush; it's just too great a risk.
I would also recommend that you pay the additional cost and get a good dual action, internal mix brush. They are so much easier to use and give you much greater control of the paint. And all the current brushes either come with, or have available, multiple sizes of tips and needles. Normally there are three; fine, medium, and heavy (or coarse). The fine tip is used with dark colored lacquers for very detailed work. The medium is the general purpose tip, and the heavy is used with light colored acrylics.
I can recommend both the Badger 150 and the Paasche VL. I have both. You might see if a friend has one or the other. Both paint extremely well with a variety of paints (though I generally use Scalecoat II). The Badger is very lightweight and maneuverable. The Paasche is heavy (relatively) and great for steady work. A lot depends on personal preference. I'm sure the other name brands are just as good -- I just don't have any experience with them.
Finally, a quality airbrush, properly cared, for will last a lifetime. So, consider the cost to be an investment. You might want to check out Badger's (
http://www.badger-airbrush.com/airbrush.htm) and Paasche's (
http://www.paascheairbrush.com/) websites for more info.
Also, checkout Harbor Freight (
http://www.harborfreight.com/). I got my VL there for $55 (about a third of the retail cost). It's not currently on their website, but it's been in and out of the catalog for the last three years. Sign up for their catalog -- it's free, and fun to look through.
When it comes to a compressor, be sure to get an oil-less (or oil free) compressor. With an oil-lubricated compressor, some oil will always mist through into the output air with disastrous results in the finish (oil and water still don't mix, nor does compressor oil and lacquer thinner). The cost of a high enough quality filter will approach the cost of an oil-less compressor. Also, be sure you get a compressor with a tank. Two gallons if fine, four is better. It results in a more even stream of air. The compressor shouldn't cost more than $75 to $100. Sears has a small compressor with tank, gauges, pressure on/off switch, etc. on sale for under $90. Auto parts stores frequently have small compressors on sale for $75 - $80. A pressure rating of 125 PSI is more than enough with 1 SCFM being adequate. Most small compressors supply 2 to 2.5 SCFM.
Kevin