Hey
check this my friend.
http://uk.pcpartpicker.com/b/Dwn
CPU
Intel Core i5-4670K 3.4GHz Quad-Core
£189.59 Aria PC
CPU Cooler
Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing
£23.62 Scan.co.uk
Motherboard Asus Z87-K ATX LGA1150
£96.95 Aria PC
Memory
Corsair Vengeance 8GB (2 x 4GB) DDR3-1600
£51.98 Amazon UK
Storage
Western Digital Caviar Blue 500GB 3.5" 7200RPM
£39.00 Amazon UK
Video Card
Gigabyte GeForce GTX 760 2GB
£239.82 Scan.co.uk
Case
Cooler Master Elite 430 ATX Mid Tower
£35.00 Ebuyer
Power Supply
XFX 550W ATX12V / EPS12V
£49.99 Scan.co.uk
Optical Drive
LG GH24NS95 DVD/CD Writer
£14.99 Amazon UK
Total: £740.94
it is little more than your budget but it is worth for this better gpu. It can play every game on high settings on 1080p.
But if you want to decrease price then you can go with gtx 660 or ti version.
I hope it helps.
Thank you.