* Is it common practice to take a lesson at a couple of different places to help choose a location and instructor you're comfortable with?
It is certainly recommended practice. Make sure you keep a note of the flight details as it should all count towards your total.
My personal recommendation would be The Pilot Centre at Denham. I'd suggest you ask to sit in the C152 and get their assessment of whether or not you can safely operate it at your height. If not, you will easily fit in the C172 or the PA28 (unless you are also over a certain weight).
I'm 6'2" and 15 stone and routinely fly a C150.
White Waltham has a buzzing social scene, but not everyone 'fits in'.
TOO