Hey Jaitea,
I was going through your wip, again (always inspiring), and that made me think about compressors.
By no meens am I an expert but here's what I'm using and from where I bought it:
http://www.harborfreight.com/1-8-eighth-hp-40-psi-oilless-airbrush-compressor-93657.html
The great thing about this little compressor is that it comes with a moisture trap and the airpressure dial is pretty accurate. Anyway, I really like it.
I don't know if you're from the USA but this is where harbour freight is based.
I'm from Montreal, Canada and was able to have it delivered to my door.
So cheers and can't wait for your future progress!