Hey guys. I will be in London next week and I am wanting to buy a customised MacBook Air. I would like to upgrade the processor, RAM and harddrive. I was wondering can this be done in a retail store? I only ask as my debit card is registered in a country that does not feature on Apple's online store billing address country list, so I can't buy it online. So if I can customise the MacBook Air in the store, I will be able to use my debit card. I have tried asking the Apple online support people, and I got three different answers from three different support people. I am hoping to buy the MacBook Air in the Stratford City Apple store, but if there are other stores in London than can customise, I am happy to go to them instead. Any advice would be great! Thanks.