As you're English though, newegg.com don't ship to the UK, so you're best off going to scan.co.uk or ebuyer.com, and looking at the 8800GTs on there. Probably be able to pick up a decent card for a nice price. If the 8800GT is a bit expensive for you, then go with a 9600GT, still decent performance.
There's a 9600GT here for around £80
http://scan.co.uk/Product.aspx?WebProductId=845006
Or spend about £20 more and get the 8800GT
http://scan.co.uk/Product.aspx?WebProductId=778183