Thanks for the advice guys, here's where I am at.
I've been dipping my toe back into the model making game as I find it very relaxing and a far better use of my spare time, although I have no idea what to do with the models once done, it is a good sense of achievement to see a finished article. My frustration has been around the smell and how long paint takes to dry, both problems solved by switching to Acrylics.
During this journey I picked up a cheapo Humbrol
airbrush, of the kind that takes an aerosol can, which was much much better than those I could get with my paint brushes (more due to my lack of skill and practice with the brush!) and, more over, it's fun! I'm getting good results with a £15
airbrush, it's the pressure I'm struggling with.
However, I've found the cans don't last long and splutter a lot as the pressure change from a full can to an empty can is difficult to manage, but I'm still enjoying this so looking for the next step up, again, dipping toe.
So I think I'm not overly bothered if this comes with two cheap airbrushes, as long as they're gravity fed (I'm using way too much paint using a feed system, especially when the paint is thinned as I can't really put it back in the pot) and work, it's the compressor I'm really after with something that'll get me by a few models before I decide to tip my toe yet further!
Based on the feedback above, it would seem to get constant pressure it's a tank I need, well that's only £5 extra
http://www.amazon.co.uk/FoxHunter-
Airbrush-Compressor-Double-Airbrushes/dp/B004XP7K9W/ref=sr_1_1?s=diy&ie=UTF8&qid=1412848488&sr=1-1&keywords=
airbrush+compressor+tank
I am now even more tempted, even if Laurie's burnt through 4 compressors!