I would strongly suggest something like this: http://www.overclockers.co.uk/showproduct.php?prodid=GX-120-HT
An HD 5670 for 60 pounds. You can probably find it cheaper on a price search engine. It'll play all modern games and make your PC compatible with practically everything.
Edit: Is your case thin? What they might be saying is that you need a 'low profile card'. So maybe the 5670 isn't appropriate.
Tease.







