I'm looking to purchase a new laptop with (X)ubuntu preinstalled. I'm in the UK so would prefer to deal with a UK company and have been recommended the Linux Emporium (which is where I bought my current Lenovo G550 from ~3.5 years ago, I've been happy with everything except the space bar) but their website has been down since before Christmas. Are there alternatives?

Before you give suggestions, please note that the following are mandatory requirements and I'm not interested in anything that doesn't include them:
*Xubuntu or Ubuntu preinstalled. Note, don't give me suggestions that have no operating system installed, I don't have the time to install the OS myself and make sure it's working.
*UK keyboard layout. If the @ is above the 2 I'm not parting with my money.
*15-16" screen.
*Delivery before the end of January, ideally sooner
*Not fragile. My current machine (Lenovo G550) is on its last legs after more than 3 years of abuse (including regularly travelling unprotected in a rucksack and being dropped on several occasions. I don't need ruggedised, just well built).
*£500 inc VAT maximum, £500.01 forget it.