You can actually order the majority of parts from a Honda Dealer in the UK (not that they'll always admit it, or be particularly helpful), but you will need to give them part numbers. You can get these from our Online Parts Manual (currently MC16, MC21, & MC28 models only).
Failing that, try a V.polite PM to StephenRC45, he may help you out, or dare I say it, TYGA Performance! They will ship anywhere, and even after doing so are usually cheaper than buying anywhere in the UK!!