Hi Simon
I have found the postal rates quite good for most things. I did bring a pair of heads in via an import/container company, slow but only about £140. You have to wait for them to fill a container but it works! All in all, when stuff gets here it seems to me to be a similar price to what you can buy from a UK retailer, maybe slightly cheaper. I have bought loads from Summit direct and it's worked fine. UPS is the best carrier (you can choose at checkout). I have found the Fedex service woefully slow, and once had a 'duty' error that they caused (incorrect computer entry) that was a right chore to sort. UPS take the duty payment on delivery. Much easier.
Chris