I've tried to kept the price low, the CPU cooler can be upgraded later as this build won't likely ever be overclocked significantly.
http://uk.pcpartpicker.com/p/2aEP3
PCPartPicker part list: http://uk.pcpartpicker.com/p/2aEP3
Price breakdown by merchant: http://uk.pcpartpicker.com/p/2aEP3/by_merchant/
Benchmarks: http://uk.pcpartpicker.com/p/2aEP3/benchmarks/
CPU: Intel Core i7-4820K 3.7GHz Quad-Core Processor (£227.99 @ Aria PC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler (£23.98 @ Scan.co.uk)
Motherboard: Gigabyte GA-X79-UP4 ATX LGA2011 Motherboard (£179.02 @ Amazon UK)
Memory: GeIL Enhance CORSA 8GB (2 x 4GB) DDR3-1600 Memory (£56.06 @ CCL Computers)
Storage: Seagate 1TB 3.5" 7200RPM Hybrid Internal Hard Drive (£65.46 @ CCL Computers)
Video Card: Gigabyte GeForce GTX 780 Ti 3GB Video Card (£539.98 @ Dabs)
Case: Corsair 300R ATX Mid Tower Case (£58.98 @ Ebuyer)
Power Supply: Corsair Builder 750W 80+ Bronze Certified ATX Power Supply (£65.99 @ Dabs)
Optical Drive: Lite-On iHDS118-04 DVD/CD Drive (£10.78 @ Scan.co.uk)
Total: £1228.24
http://uk.pcpartpicker.com/p/2aEP3
PCPartPicker part list: http://uk.pcpartpicker.com/p/2aEP3
Price breakdown by merchant: http://uk.pcpartpicker.com/p/2aEP3/by_merchant/
Benchmarks: http://uk.pcpartpicker.com/p/2aEP3/benchmarks/
CPU: Intel Core i7-4820K 3.7GHz Quad-Core Processor (£227.99 @ Aria PC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler (£23.98 @ Scan.co.uk)
Motherboard: Gigabyte GA-X79-UP4 ATX LGA2011 Motherboard (£179.02 @ Amazon UK)
Memory: GeIL Enhance CORSA 8GB (2 x 4GB) DDR3-1600 Memory (£56.06 @ CCL Computers)
Storage: Seagate 1TB 3.5" 7200RPM Hybrid Internal Hard Drive (£65.46 @ CCL Computers)
Video Card: Gigabyte GeForce GTX 780 Ti 3GB Video Card (£539.98 @ Dabs)
Case: Corsair 300R ATX Mid Tower Case (£58.98 @ Ebuyer)
Power Supply: Corsair Builder 750W 80+ Bronze Certified ATX Power Supply (£65.99 @ Dabs)
Optical Drive: Lite-On iHDS118-04 DVD/CD Drive (£10.78 @ Scan.co.uk)
Total: £1228.24