Which airbrush should I buy?

Very sound advice. Plan on lots of practicing; it won't be an overnight success but it WILL happen. Buy an airbrush (a Badger 155 Anthem in my case) was one
of the best purchases I've ever made. Best of luck with it.
Paul

Regarding extra parts:

If you are careful and take care of your airbrush, the parts will last a long time. If it comes with a protective 'cap' for the needle, USE IT! My needle sticks out from the end of the brush and it would be very easy to bump it or damage it if I didn't use the cap. I have a couple of extra needles and nozzles, but so far I'm still using the original that came with the brush.

M.

i think a lot of the time it comes down to personal choice, your budget and what you want to use it for.
i own a aztek 470 and learnt to airbrush using this. it is fairly forgiving and quite versatile. every time i use it i feel guilty that i haven't cleaned it properly, ie i cant get in to clean some noks and crannies, but saying that it usually needs a quick blow through with a bit of gun was.
i am thinking about buying a new brush such as an iwata or paashe, they can be pulled apart and cleaned in pieces. also if a piece malfunctions you only have to replace a singular part not the whole brush. but pulling apart a brush will also wear the parts, which may lead to the need of replacement.
i would suggest that the azteks lend themselves more towards the model market while brands such as iwata lend themselves more towards the art world.
do not quote me on this but i would describe the azteks like a family car, does the job and very versatile, whereas iwatas are like your sports car, a much better product, but you pay the price to buy.

buy an aztek if you want a 'family car' affordable does the job and versatile. buy an brand such as iwata if you want to have a 'sports car', expensive but nothing else compares. i think mike said it best if you are only painting models get something like an aztek. i own a aztek and it is great for modelling but i am thinking about getting an iwata or something similar to do artwork with. i haven't used an iwata but have read that they are one of the best for finishes and detailing.... once you got the hang of airbrushing. read any airbrushing magazine and you will only see iwatas, paashe, olympic being used but in modeling mag azteks are slightly more common.
a lot of it comes down to peronal choise and budget. ie some people don't like the rear mounted air inlet on the azteks or the fact you can't pull it appart to clean.
get something that you feel you can master. a good fnish with a crap airbrush compared to a crap finish with a good airbrush is by far better.
the aztek 470 has the advantage where you can use it as either a double or single action brush. (i am unsure if any other brushes offer this feature). the aztek doesn't have to be pulled appart to be cleaned. pulling appart a brush can be a bit dounting for some people the first time.
i recomend if you haven't used an airbrush before get a nice cheep one, learn how to use it and work out what features you want in your 'good' airbrush.

Alright I will put my 2cents in on this topic. I have several Aztec and Testor Airbrushes. I have the five year aniversary set that has the 470, and the 270?? (I think) I also have a 3000S, and three other smaller Testor model airbrushes. I like the Aztec because of its ease of cleaning and use. YOU NEVER HAVE TO OPEN THE BODY!!!. I have turuette's and I think that if I had to stumble with all of those parts I would go crazy. I like the way I can change nozzels and colors on the fly and I love it's lightweight and the feel of the airbrush in my hands.

f-4's rule the skies...