COOLER MASTER HAF 932 Advanced RC-932-KKN5-GP Black Steel ATX Full Tower Compucase Case with USB 3.0, Black Interior and Four Fans-1x 230mm front RED LED fan, 1x 140mm rear fan, 1x 230mm top fan, and 1x 230mm side fan $149.99 and a $10 rebate with free shipping.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119160
EVGA Z68 FTW 160-SB-E689-K2 LGA 1155 Intel Z68 SATA 6Gb/s USB 3.0 Extended ATX Intel Motherboard $299.99 and a $10 rebate.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813188099
Intel Core i5-2500K Sandy Bridge 3.3GHz (3.7GHz Turbo Boost) 4 x 256KB L2 Cache 6MB L3 Cache LGA 1155 95W Quad-Core Desktop Processor BX80623I52500K $219.99.
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115072
G.SKILL Ripjaws X Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-14900CL9Q-16GBXL $149.99
http://www.tomshardware.com/forum/321065-31-build-%C2-2000
2x-MSI N580GTX Lightning Xtreme Edition GeForce GTX 580 (Fermi) 3072MB 384-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card $1199.98.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127589
Corsair Force Series GT CSSD-F120GBGT-BK 2.5" 120GB SATA III Internal Solid State Drive (SSD) $219.99.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233191
Western Digital Caviar Black WD2002FAEX 2TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive $139.99.
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136792
High Current Pro HCP-850 850W TX12V v2.3 / EPS12V v2.92 SLI Certified CrossFire Certified 80 PLUS GOLD Certified Modular Active PFC Power Supply $199.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371053
Thermaltake CLP0575 Frio OCK Universal CPU Cooler Ultimate OverClocking King Supports up to 240W TDP Dual 130mm VR Fans $68.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16835106178
LG Black 12X BD-ROM 16X DVD-ROM 48X CD-ROM SATA Internal Blu-ray Drive Model UH12LS28 OEM LightScribe Support - OEM $69.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16827136232
Microsoft Windows 7 Professional SP1 64-bit - OEM $139.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16832116992
LG W2753VC-PF 27" 2ms Full HD Tilt & Swivel Adjustable WideScreen LCD Monitor300 cd/m2 50000:1 $339.99.
http://www.newegg.com/Product/Product.aspx?Item=N82E16824005161
The total for this Super build is $3197.88 US or 2,022.90 GBP You might be able to find these components in England cheaper since you are used to shopping there as you can see I pulled these off the Newegg site.