That site appears to be no more than a test document. It has been compiled from standard shopping site software but the company name and address have never been entered into the relevant fields, neither have the 'terms and conditions' or the 'contact us' details. It's impossible to order anything from the site (but, equally, it's impossible for them to take money from anyone).
The domain name was only registered a few months ago and it looks like the company has yet to get off the ground. If it's genuinely UK-based it would be illegal for them to trade on the internet without providing a postal address but, since they've not started taking people's money yet, they're currently doing nothing illegal.
The person who registered the domain name has used 'WhoisGuard' to hide his (or her) identity. That suggests that it's a 'one man band', planning to operate from a home address. Big companies never hide their identities because (a) they're in the public domain anyway and (b) they've got a proper business address, rather than something like 'Flat 5, 6th Floor, Mandela Towers, Clapham'.
The site is actually hosted on a US server, but that's not particularly unusual (or suspicious). To email the site owner, highlight the following email address (by holding down your left mouse button while dragging across the address):
[email protected]
Right-click and select copy. Create a new email. Right-click in the address field and select paste.
Chris