ive only recently started and bought a compressor with a built in tank.
not an expensive one, but it works great.
i also bought a couple of cheap airbrushes made by Veda which were good
but i just bought a veda with an adjustable Air valve and it is great.
i know the Paasch and Iwata purists will frown at it, but it works great for me and very adjustable.
It only cost £25 from Amazon, but ive just finished spraying some latex onto a mask and it never coughed once!,
the cheaper ones have sprayed acrylics and enamels very well, but didnt fare so well with latex.