I currently fly with Leading Edge and they are indeed a good bunch however, having some experience of both the outfits at prestwick, I think that your location and desire to progress quickly point at prestwick flight centre being the most likely "best fit" Do not underestimate the grind of an hour plus driving too and from the airport. Please don't think ive anything against prestwick flying club....they are about th e only true flying club ive found in the area and I would be a member if I lived closer but that informality and part time operation may not suit if you want to fly on a regular basis midweek.
PS. if you do choose leading edge, you may find it worth the extra 15 pounds per hour to fly the pa28....its just so much nicer!