I gather there are three 'specialists' for this kind of thing; Fensport, Litchfield and Abbey Motorsport. I'm going for Litchfield mainly because I'm lazy - they're half an hour up the road where Fensport is +3 hours each way. Booked in for Friday week so will report back.
I'll admit I'm getting a little **** off with Litchfield though. They never call back and it's hard work getting answers. May yet switch to Fensport. I've asked a few extras and twice they've said they'll call back but **** all response.
Have been speaking with Tony of Fensport who has been very helpful, returns calls, replies to emails and is generally interested in my money. Order placed, should be done the end of this month. Looking forward - much!