Declaration of interest: I fly from there, but am not involved with the instructing side so get no benefit from this post.
I'd look seriously at White Waltham then. A couple of Super Cubs, three grass runways, loads of instructors, interesting biplanes to progress onto, and several towns within a few miles (nearest Maidenhead) which should have plenty of places to stay, eat, and spend an evening.
Not cheap, but they're obviously trying to market themselves as a "quality product", and have about the best clubhouse to sit around in I know in England.
G