Hi,
Your best bet would be to visit both schools and have a look around and a chat with them and idealy a chat with a couple of students for feedback.
Then make your own mind up on which you prefer of the schools available.
You could get yourself a pilots log book around a tenner and try a trial lesson at both to see what you think of the aircaraft they use and what the instuctors are like, the hours logged will count towards your total hours required in your training.
The golden rule is NEVER pay up front although there may be a discount always pay as you go.
Good luck,
Steve