As John says it depends on your budget. I have a Harder & Steenbeck Evolution plus, and find this to be a first class tool and for me would highly reccomend. Its also very easy to clean. John at Scale Model Shop on this site supplied mine with fast faultless delivery.
I too am a fan of the H&S Evo, a great brush. I would recommend two needle sets for modelling, a 0.4 for wider areas and a .2 for detail. I recommend not touching a 0.15 as it is too small for model paints and it will give a lot of problems. As for a compressor, the AS186 is excellent and cheap.
If you want a AS189S (the new one with a fan in it) they are due in Friday or Tuesday, I'm just waiting for confirmation of the date, as for airbrushes I've just had a delivery from H&S so I have plenty in.