This is what I have now - the biggest 15amp I could afford at the time. It does seem to collect alot of moisture though - it has a handy drain tap at the bottom of the tank - I always open it up after use to drain any moisture out of the tank. the Air Macs are used alot in the orchards around here so they can take a bit of abuse.
When you do get a new compressor you can always join the two together and gain abit of performance that way.
Have you thought about buying a bigger compressor and motor and attaching that to your existing tank? May be a cheaper way to go.

