Graham the kit in the states is the same one on my car just I use a td04 turbo not the gt28rs alot of those guys use
and obviously I have the 10psi version
You will need it to be mapped though as IIRC the fuel in america is only something like 91ron so the tunes that come with the kit will need a re-adjust
And if you want to come out in mine i'd be more than happy to take you for a spin m8 but I don't know where you live?
Oh and mine has been running like this for other a year and a 1/4 now so I think it's fairly ok to prosume 10psi is ok on std internals (thats what most the boys in the states do)