My research has shown that you get what you pay for with Air Compressors, and you'll need a minimum of 12 FAD for a decent spray job. I'd also recommend a belt driven unit so you don't send yourself (and neighbors) crazy from noise. Unfortunately, I think you need to double your budget to find what you're after.
This is the one I'm planning on getting next month:
http://www.machineryhouse.com.au/C340It's a good quality unit, and should last a lifetime if well maintained, however even this won't do a good spray job though as it's only 8.4 FAD.