So I've just ordered the Switzer AS186 (From here) as my first airbrush. It's gotten some good reviews  as a first airbrush. I'm intending to follow this tutorial. Terry is an excellent teacher and he uses airbrushing for basecoating and the base colours, with zenithal highlighting, which I think should be manageable for a first time user. The rest is washes, drybrushing and regular layering techniques. 

I'm a little apprehensive of using a £70 airbrush/compressor kit!

I'll post again when I receive the airbrush with initial impression.