Personally I prefer the "garage" style compressors, as I have my hobby room plumbed for air. Currently I have a 3 gallon tank (around 27 liters using the bigger British gallon), when and if it passes on to the big compressor spray booth in the sky, I'll replace it with a 5 or 10 gallon tank. Then again, I a tool pig!
The bigger the tank, the less the compressor has to work, the longer the compressor will likely last. Depending on your own personal setup, you may find that it works very well.
Tanks can collect a far amount of moisture. You'll find that there is a drain on the tank to remove the excess water. Make sure that you have a moisture trap located as close to the airbrush as possible. I ended up with three in total: one at the tank, one at the regulator mounted in my spray booth and an inline one on the hose to the airbrush. Water and paint do not play together well!