I don't own an airbrush, due to the fact that it's too expensive for me. When I need to paint large surfaces, I use a wide flat brush with Tamiya acryllics. They often require more than one coat to get good coverage, but they work out well in the end.
Of course, if you're buying an airbrush, then that's really the only way to go.
Good luck and make sure you post some piccies!
![Big Smile [:D]](/FSM/CS/emoticons/icon_smile_big.gif)
Cheers,
John