Yup, they're the ones - in Kent.
£500 is OK for a custom re-map. A generic remap costs between £300 and £400 generally, customs can be a little or a lot more. MRC Tuning up in Banbury do a good package for a custom tune with a Milltek Exhaust. I was thinking of popping into those guys to get it done as I've had a couple problems with the exhaust, but I can't justify £1,000 at the moment. Plus, I'd want a Forge 007 diverter valve put on too and new boost hoses as I seem to have a slowly increasing lag on acceleration.