Karl Norris (Norris Motorsport) is quite near you,he's in Alfreton, he's an Omex dealer, give him a call for some advise.He is awesome with cossies,he also tunes the Focus rs mk1, see what he has to say, nice bloke is Karl and will offer endless options/advise as he sees fit.

Another Omex dealer is PJ Motorsport in Birmingham,the owner is Paul, maybe worth a chat to him to,Paul also has a hub dyno on site, depends how you wanted the car mapped/set up on the road or on a dyno.
I hope this helps you.

CheeRS.Lee.