PCPartPicker part list:
http://uk.pcpartpicker.com/p/2oNW0
Price breakdown by merchant: http://uk.pcpartpicker.com/p/2oNW0/by_merchant/
Benchmarks: http://uk.pcpartpicker.com/p/2oNW0/benchmarks/
CPU: Intel Core i5-4670K 3.4GHz Quad-Core Processor (£164.99 @ Aria PC)
Motherboard: Asus Z87-A ATX LGA1150 Motherboard (£103.04 @ Scan.co.uk)
Memory: G.Skill Sniper Series 8GB (2 x 4GB) DDR3-1866 Memory (£65.52 @ Amazon UK)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive (£42.00 @ Aria PC)
Video Card: Zotac GeForce GTX 780 3GB Video Card (£400.54 @ Scan.co.uk)
Case: Zalman Z11 ATX Mid Tower Case (£42.50 @ Ebuyer)
Power Supply: Corsair CX 600W 80+ Bronze Certified Semi-Modular ATX Power Supply (£58.09 @ Dabs)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer (£11.98 @ Ebuyer)
Total: £888.66
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-12-23 19:13 GMT+0000)
You could change the GPU for a slightly worse R9 280x if you wanted to, it's much cheaper.