Right, here's the revised spec:
Arctic Cooling Freezer 7 Pro - P4 up to 4.4GHz - S775 Dual/Quad Core Ready £15.97
Microsoft Windows Vista Home Premium SP1* 64Bit 1Pk OEM (DVD)£88.42
Samsung SH-S223F/BEBE 22x DVD±R, 12x DVD±R, DVD+RW x8/-RW x6, SATA, Black, OEM £14.93
Intel Pentium Dual-Core, E5200, Socket 775, Wolfdale Core, 2x2.5 GHz, 2MB Cache, Retail £64.85
Biostar TP45 HP, iP45, S 775, PCI-E 2.0 (x16), DDR2 1066/12006/667/800, SATA II, SATA RAID, ATX £90.24
and the antec nsk4480 ATX case with the 380w psu here:
http://www.ebuyer.com/product/130947
All coming to a grand total of £337.40