My advice would be find an instructor who you feel comfortable with and has a real passion for flying and not just building hours for the airlines...
I don't know what its like in the UK but in Aussie alot of flying schools are sausage factorys for overseas students and these should be avoided like the plague!
Also the smaller aeroclub type schools offer more of a social network which is great for things like trips away on weekends, while training for my PPL I went on every club trip and you have opportunity to experience and learn things you wouldn't normally get to do.
Good luck
