I agree with everyone else as the choices for your needs are almost endless.
Practically any brand made would suit your needs but I personally would stay away from Aztek as they seem to have too many problems that normal airbrushes do not have.
The gravity-feed models are a little easier to clean but they are not a lot easier to clean than a siphon-feed model.
The Badger Anthem that was mentioned is a great all around airbrush and it has some features that are nice. It breaks down faster than any other airbrush manufactured and it comes with a PTFE (Teflon) needle bearing.
So it all boils down to which one you like and what fits your budget.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon