i was wondering where you would buy an airbrush for cake decoration, and what you use for "paint"

check out tcpglobal.com and you would use something like amerimist a food grade airbrush paint. tcp sell kits at a great price. It is where I got mine.

I bought my systems from amazon. Here is one that's reasonably priced and very portable and compact comes in several colors too.

http://www.amazon.com/dp/B003KKJDDC/?tag=cakecentral-20

Check out harbour freights thats where I got mine $59. for the compressor and the airbrush was something like $10-$14
Love it.