Thanks. Here is my updated list. I'd love opinions on it:
Processor: Intel Core 2 Quad Q6600 £137.95
Motherboard: ASUS P5KC AiLifestyle Series £72.82
Memory: OCZ 4GB (2x2GB) DDR2 800MHz £69.99
Graphics Card: Point Of View 8800GT 512MB £119.98
Hard Drive: Already got (Seagate Barracuda 500GB SATA 7200.9) £0
DVD/CD Drive: Pioneer DVR-215BK 20X SATA DVD±RW £17.99
Power Supply: OCZ StealthXStream 600W PSU £47.58
Operating System: Microsoft Windows Vista Home Premium £62.96
Cooling Fan: Arctic Cooling AC-FRZ-7P £15.24
Case: I-Cute Black UL01 Mid Tower Case £20.99
Front Case Fan: Hiper 120mm Case Fan £5.99
Rear Case Fan: Hiper 120mm Case Fan £5.99
Total: £577.48