Certainly look in to Glasgow. But as a student at Glasgow University, I've been hiring from Cumbernauld Flying School for two years and can only recommend them.
They use Katanas (which are more complex than their C152/PA38 equivalents due to a variable-pitch prop) and their facilities, instructors and general atmosphere can only be described as more welcoming than Glasgow. Besides, you're not wasting money and time waiting at the holding point behind a 737 waiting for clearance. I know people will whine that you don't get the same experience with ATC at Cumbernauld (air-ground radio) but the argument is that at Cumbernauld you have the choice. There is nothing stopping you (if Glasgow let you) from flying a local over the city and across the approach path towards the west coast (Oban and Prestwick both within easy reach).
My advice is that you simply must train at Cumbernauld. Better planes, newer planes, more available planes/instructors, cheaper, friendlier. Not only are the staff at the school welcoming, but the staff working at the airport (the name Stuart springs to mind) are always willing to help you out if you're in need.
Email me if you want. You're welcome to come up with me next time I'm flying.
