Hi guys, New desktop pc? HELP!!!

Hi guys... im looking at a new desktop pc from littlewoods, its a pay monthly shop in the UK,
http://www.littlewoods.com/electricals/desktop-computers/e/b/4877.end

I am basically asking for help from people with knowledge on computers, wanting to run wow in ultra graphics with a fairly big screen, i dont want to spend more than £1000, so.. id appreciate your help when you have the spare time, thanks guys

<3 ucks