In my view the choice of airfield and or flying school is very much a secondary consideration to the choice of instructor.
In my experience you will get better value for your money from an experienced, career instructor who's instructing because they enjoy it, than you will from a low hour newbie who is only instructing because they have to until they get enough hours for an airline job.
You're going to be spending quite a bit of money, so do some research, go to a few places, chat to several instructors and go with the one you get on with the best.
Finally, remember that the lowest hourly rate won't necessarily mean the lowest overall cost.