Alright so I came up with one build:
PCPartPicker part list:
http://uk.pcpartpicker.com/p/25D3A
Price breakdown by merchant: http://uk.pcpartpicker.com/p/25D3A/by_merchant/
Benchmarks: http://uk.pcpartpicker.com/p/25D3A/benchmarks/
CPU: Intel Core i7-4770K 3.5GHz Quad-Core Processor (£227.99 @ Aria PC)
CPU Cooler: Corsair H100i 77.0 CFM Liquid CPU Cooler (£87.99 @ Amazon UK)
Motherboard: Gigabyte GA-Z87X-UD4H ATX LGA1150 Motherboard (£134.98 @ Amazon UK)
Memory: G.Skill Ripjaws X Series 16GB (2 x 8GB) DDR3-1866 Memory (£142.49 @ Amazon UK)
Storage: Samsung 840 Series 120GB 2.5" Solid State Disk (£78.99 @ Amazon UK)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive (£61.40 @ Amazon UK)
Video Card: EVGA GeForce GTX 780 Ti 3GB Video Card (£559.99 @ Scan.co.uk)
Case: Fractal Design Define R4 (Black Pearl) ATX Mid Tower Case (£77.00 @ Amazon UK)
Power Supply: SeaSonic M12II 750W 80+ Bronze Certified Semi-Modular ATX Power Supply (£87.30 @ Scan.co.uk)
Optical Drive: LG GH24NS95 DVD/CD Writer (£12.36 @ Amazon UK)
Operating System: Microsoft Windows 8 (OEM) (64-bit) (£69.99 @ Ebuyer)
Monitor: Asus VS238H-P 23.0" Monitor (£139.44 @ CCL Computers)
Monitor: Asus VS238H-P 23.0" Monitor (£139.44 @ CCL Computers)
Monitor: Asus VS238H-P 23.0" Monitor (£139.44 @ CCL Computers)
Total: £1958.80
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-11-20 21:38 GMT+0000)
I went a bit overkill on the RAM but that can be changed. Also for the graphics card I would personally get a R9 290(x) because they perform better for the price but none seem to have any decent coolers on them yet since it's a pretty new card. I'm sure there are cheaper options for other parts too so you may be able to get 2x graphics cards in crossfire or SLI.