Need a PC for less than £900

I'm looking for a PC for less than £900, preferably around the £700/800 area. I know I can build my own with relatively no experience, but for starters I don't have the time and I can't exactly give myself 12 months warrenty.

Also, I know there are sites that create your own PC specs but I'd rather go with a legit company with a good customer service.

I'm looking for a gaming PC primarily that can play things like Batman Arkham Asylum on highest settings (resolution and PhysX don't particularly mean much to me ) but I do have a 1080p HDTV with a HDMI cable that I'd like to make use of. Soo I don't need a monitor.

Please link me to a site you have used in the past that you trust and can offer a PC that I want. I'd like it to be legit site.

I'm not looking for the most up-to-date parts, maybe some sort of Quad-Core PC and a mid-high range graphics card. Something that can play any game I want (including Crysis). Again resolution doesn't matter much to me but if I could play on the highest resolution that'd be sweet.

or more specifically:

http://www.overclockers.co.uk/show [...] 45&subcat=

http://www.overclockers.co.uk/show [...] 44&subcat=

http://www.overclockers.co.uk/show [...] 44&subcat=

The top one is AMD-based and comes with the latest Radeon 5780

The middle one comes with an overclocked i7 920 with the option of taking the GPU up from the standard 4850

The last one comes with an overclocked i5 750 and you can choose the case.

Overclockers are awesome.

http://www.overclockers.co.uk/show [...] 44&subcat=

Chuck a 4870 in it and you'll have a great gaming rig. The i7 is a seriously powerful CPU. It'll cap COD 4 at 91 FPS at 1600x1050 max settings inc full AA. I have pretty much the same setup. For £800 your getting a lot of PC. Don't bother with Comet.