If you're north of Northolt, you can should also have a look at the various options at Elstree, listed here
Agree with the others - go for (at least one) trial lesson and choose as a function of how you like/get on with/trust the instructor and the impression the school gives you, as well as the planes themselves.
Enjoy :-)
B.
I recently used Jose McVicar at the Lion Flying Group to do my LPC. Personally I think she's great. Really knowledgeable, and really calm, just what you need.