Its an old thread now but emerald is run by dave walker, from the town i live in, he has a coloumn in practical performance car which is worth a read. Some of the cars that come through his place are unreal, from dakar race buggies to v8 rx7's and numberous race teams from across europe so he must be doing something right! Its not cheap though, about £600 notes plus will need wiring in then mapping about another £400 from him ,but they are top notch gear.