Well...   here is the direct link to newegg.com - I don't know if they ship to the UK. But then....  you should be able to find it "over there" as well. XP64 bit has been out for quite some time - more than a year I believe - and it's been running here (on four machines - soon to be six) without a hitch. Love it!

http://www.newegg.com/Product/Product.asp?Item=N82E16832116053

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