I assume this is Coral gym in Hove you mean btw. Sports injuries clinic with Paul... http://www.coralfitness.co.uk/sports-injuries-clinics
I'm about 40 mins away but will happily go for £40 on a recommendation - always worth a try...
Another vote for Paul. If you are stretching your glutes have a look at the YouTubes on Seated Glute Stretch and Hip Flexor Stretch. Both are really helping my knee problem which was actually a hip and back problem.