Good Airbrush for a Beginner

[Opus Krokus]

I saw the new line of GW paints and that got me to thinking about jumping in. When I searched the lounge, the info looked like it might have been a little stale. Is there a good brush for starting out? I don't know if they make them this way, but I was thinking about something that I could upgrade as I get better (assuming I keep at it long enough to improve). Thanks!