in East Anglia there are a lot of tuners available who could help you, all franchises of one guy called Nick Lawrence who is a very good tuner originally based in Lowestoft, now based in Nurbergring.
If you are considering a remap look on his website for the nearest franchise.
(he writes all the maps, the guys just physically upload and download on his behalf)
I've had three remaps off him - enough said.
Mondeo TDCI 2.0 130 - massive difference, pulls like a train. 8.8 to sixty vs 9.8 stock.
Volvo s60 t5 geatronic 6.9 stock, 6.0 - 6.4 modded depended on fwd grip
http://www.on-cars.com/
NO I AM NOT SPONSORED OR AFFLIATED BUT IVE HAD 3 MAPS OFF HIM