i already suggested this in another thread but ill suggest it again
i would get this
i7 920 - £197
http://www.ebuyer.com/product/161171
Foxconn flaming blade gti x58 - £111.65 which includes vat
https://www.pricelover.com/product/020F1664BA5-00/
pny 3gb ddr3 1333mhz 1.5v - £39.99 + free postage
http://www.play.com/PC/PCs/4-/11102616/PNY-PC3-10660-3GB-1333Mhz-DDR3-240pin-DIMM-Computer-Memory/Product.html?&_$ja=tsid:11518|cc:|prd:11102616|cat:Memory
and 2 hd 5770 for crossfire - about £221 inc vat
https://www.pricelover.com/product/A.../HD-577A-ZHFC/
Total for ram,mobo,cpu and gpu = £569.69