anyways i just looked at some comonents and i'm not sure if the 850 pounds is only for the components you listed or for a whole comp including monitor.. but i picked only the type of parts you picked.. except better.. and well here it is..
Intel Core 2 DUO E6600 "LGA775 Conroe" 2.40GHz (1066FSB) - Retail (CP-128-IN)
Price: £204.99 (£240.86 Including VAT at 17.5%)
http://www.overclockers.co.uk/acatal...aCP_2d128_2dIN
Gigabyte GA_965P_DS3 (Socket 775) PCI-Express DDR2 Motherboard (MB-061-GI)
Price: £89.95 (£105.69 Including VAT at 17.5%)
http://www.overclockers.co.uk/acatal...aMB_2d061_2dGI
G.Skill 2GB DDR2 NR PC2-6400 (2x1GB) CAS5 Dual Channel Kit (F2-6400PHU2-2GBNR) (MY-014-GS)
Price: £129.99 (£152.74 Including VAT at 17.5%)
http://www.overclockers.co.uk/acatal...aMY_2d014_2dGS
Connect3D ATI Radeon X1900 XT 512MB GDDR3 AVIVO TV-Out/Dual DVI (PCI-Express) - Retail (3056) (GX-047-CO)
Price: £169.95 (£199.69 Including VAT at 17.5%)
http://www.overclockers.co.uk/acatal...aGX_2d047_2dCO
Seagate Barracuda 7200.10 320GB ST3320620AS SATA-II 16MB Cache - OEM (HD-078-SE)
Price: £59.95 (£70.44 Including VAT at 17.5%)
http://www.overclockers.co.uk/acatal...aHD_2d078_2dSE
Subtotal £654.83
VAT £114.60
Total £769.43