PCPartPicker part list:
http://uk.pcpartpicker.com/p/68NDmG
Price breakdown by merchant: http://uk.pcpartpicker.com/p/68NDmG/by_merchant/
CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor (£245.94 @ Aria PC)
CPU Cooler: Corsair H100i 77.0 CFM Liquid CPU Cooler (£78.88 @ CCL Computers)
Motherboard: Asus Z97-A ATX LGA1150 Motherboard (£106.19 @ Aria PC)
Memory: Kingston HyperX 16GB (2 x 8GB) DDR3-1600 Memory (£110.25 @ Amazon UK)
Storage: Crucial MX100 256GB 2.5" Solid State Drive (£74.39 @ Aria PC)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive (£55.14 @ Aria PC)
Video Card: MSI GeForce GTX 970 4GB Twin Frozr V Video Card (2-Way SLI) (£274.99 @ Ebuyer)
Video Card: MSI GeForce GTX 970 4GB Twin Frozr V Video Card (2-Way SLI) (£274.99 @ Ebuyer)
Case: NZXT Phantom 410 (White) ATX Mid Tower Case (£65.99 @ Novatech)
Power Supply: EVGA 750W 80+ Gold Certified Fully-Modular ATX Power Supply (£81.87 @ Amazon UK)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer (£10.09 @ CCL Computers)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) (£69.29 @ Aria PC)
Monitor: AOC G2460PQU 144Hz 24.0" Monitor (£193.99 @ Amazon UK)
Monitor: AOC G2460PQU 144Hz 24.0" Monitor (£193.99 @ Amazon UK)
Keyboard: Cooler Master CM Storm QuickFire TK Wired Gaming Keyboard (£72.89 @ Amazon UK)
Mouse: Mad Catz R.A.T. 5 Wired Laser Mouse (£45.47 @ Scan.co.uk)
Total: £1954.35
Prices include shipping, taxes, and discounts when available
Don't really need a gtx 980 sli when a gtx 970 sli will work just as well. With this build you can tell your friend to enjoy a $50 savings, and tell him to spend it on icecream when he gets the chance.
@qwazwaz You listed a solid build but if you check the UK stores the parts you chose will go over his budget, it isn't as simple as just converting the USD into UK pounds as the stores in UK sell the parts at different prices.
@iamlegend The OP said his friend wanted a future proof build, it's not overly solid advice to say to go and buy parts later. Also the monitor you chose is the best monitor you can really get for gaming BUT it is out of stock in a lot of places or it would be sold overpriced in places like amazon. Apart from that I wouldn't change the cpu/motherboard/gpu but why go with just 8gb of ram, and just a small 120 gb ssd when he can get 16gb of ram and 256gb ssd for his budget? AMD ram and ssd's aren't that good compared to other brand's parts so not too sure why you would stick with AMD parts...
@OP No need to really go too overkill with the very best monitor, medium sized 144hz monitors such as the ones I chose in my build will be excellent while gaming, and it is not too small nor big. I hope you liked the case I chose, I personally love the look of it but the case is a personal touch, change the case if you don't like it or keep it, it is up to your friend really, as awesome cases just make the experience better.