PCPartPicker part list:
http://uk.pcpartpicker.com/p/XK9Pgs
Price breakdown by merchant: http://uk.pcpartpicker.com/p/XK9Pgs/by_merchant/
CPU: AMD A10-6800K 4.1GHz Quad-Core Processor (£93.59 @ Aria PC)
Motherboard: MSI A88XM-E35 Micro ATX FM2+ Motherboard (£37.18 @ Amazon UK)
Memory: Kingston HyperX T1 8GB (2 x 4GB) DDR3-1600 Memory (£38.37 @ PC World Business)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive (£35.94 @ Aria PC)
Video Card: XFX Radeon R9 270 2GB Double Dissipation Video Card (£129.92 @ Scan.co.uk)
Case: Thermaltake Versa H22 ATX Mid Tower Case (£26.24 @ Scan.co.uk)
Power Supply: XFX 550W 80+ Bronze Certified ATX Power Supply (£44.11 @ CCL Computers)
Optical Drive: Lite-On iHAS124-14 DVD/CD Writer (£11.27 @ Scan.co.uk)
Sound Card: Asus Xonar DS 24-bit 192 KHz Sound Card (£33.82 @ CCL Computers)
Total: £450.44
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-06-20 15:23 BST+0100
I put in a 7.1 setup sound card with better sound. The motherboard already offers decent sound. But you wanted a sound card. And you can pick up a monitor with the remaining.