Haven't done much flying with a tin thermal up front, but I can point you in the direction of info.....
Take look at the BGA website, thats
www.gliding.co.uk There is a clickable map there. That will give you websites for all the UK gliding clubs. Also for general opinions and suchlike have a look at
www.gliderpilot.net which has various formus and the like.
As you'll see from the map there are plenty of clubs around from some tiny ones with a handful of members, to places like Lasham, which are professionally run. I've been a member of Southdown GC (which is probably a bit far from you) for the last couple of years, and I have no complaints other than on a good day a sea breeze front can roll in, which tends to curtail soaring.
Best idea is to wander down to a few clubs, chat to the members, and get a trial lesson to see what you think of things. One other thing to bear in mind is that while the hourly airborne cost is lower (club gliders run about £20/hr, £15 to £20 for an aerotow to 2000, £5 for a winch launch) the actual time spent at the airfield is quite large and people are generally expected to muck in and help launch and fetch gliders. That said, it keeps you fit, and beer in the bar afterwards tastes all the better....
Have fun....
EJ