The best place to contact would be the British Aerobatic Academy, not so far from Oxfordshire (they're based at Little Gransden, Cambs) and specialise in 'lifesaver' training in spins and unusual attitudes, as well as all manner of aerobatics of course! Oh, and the Extra 200 they use for their main training is a lovely aeroplane to fly and not overly expensive!
Parachute not mandatory!
Aerobatic flying training | British Aerobatic Academy