Depends how far you want to go!
As the others have said
Cambridge have an extra 200, don't know how good the instruction is
but at the price is the best bang for the buck. will take you from beginner to advanced aeros, but it will spoil you if you end up doing to subsequent hours in a say a slingsby!
British aerobatic academy, I think based at little Gransden, might have moved to bourne also have an extra 200. (also Cambridge area)
Personally, try Tiger Club at headcorn.
cap10c is a good plane to learn in and if Richard Pickin is down there you wont find a better instructor in my humble opinion. once you are good enough you can do aeros overhead the air field - saves you a LOT of time and money