the £5.5k conversion just adds another pair of injectors and these are run off a piggyback ecu
also the conversion also doesn't replace the tb, they reuse the 58mm
so it must be possible to sort the fuelling and use the 68mm on a diy basis
If I have to go to the states I will try and bring back a sc kit in my suitcase, I will declare it, I can't see a problem rofl..