[GREG]

About £800 to £2500 depending on the kit and who fits it.

You can always find all the bits and bobs on ebay very cheap to do it but most professional installers will send you away with a flea in your ear so you would need to find a competent mechanic to fit it all together and then get it tested. It would be the cheapest route and maybe the new Bristol company could help ?

I believe that the engine compression needs to be ramped up a bit and the cooling needs improving, along with going up to 10mm HT leads

Get some proper advise :-) The installer I talked to is near Tadcaster so a long way from you ! He reckoned around £800 for my 408 a couple of years ago.