My First Gaming Pc Build

I can't speak for most of it as I'm not familiar with UK currency, however I would definitely try to get a modular psu if you can swing it, I just did my first build in the same case and cable management was a huge pain to do(I got a non modular psu)
 


 
CPU + MB - You have a non-overclocking CPU paired with an overclocking motherboard. Look toward the H97 chipset for a MB
MEM - H97 is limited to DDR3-1600.
PSU - XFX, Seasonic, the EVGA G2 lineup, or filter through the Tier 1 or Tier 2 list. www.tomshardware.com/forum/id-2547993/psu-tier-list.html
WIRELESS - Changed to a model that supports AC

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4460 3.2GHz Quad-Core Processor (£138.52 @ More Computers)
Motherboard: Gigabyte GA-H97M-HD3 Micro ATX LGA1150 Motherboard (£64.80 @ Aria PC)
Memory: Corsair Vengeance 8GB (2 x 4GB) DDR3-1600 Memory (£35.98 @ Amazon UK)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive (£39.98 @ Scan.co.uk)
Video Card: MSI Radeon R9 380 4GB Video Card (£178.98 @ Amazon UK)
Case: Corsair SPEC-01 RED ATX Mid Tower Case (£41.41 @ CCL Computers)
Power Supply: XFX TS 550W 80+ Gold Certified ATX Power Supply (£37.99 @ Amazon UK)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer (£9.38 @ CCL Computers)
Operating System: Microsoft Windows 7 Home Premium SP1 OEM (64-bit) (£67.95 @ Ebuyer)
Wireless Network Adapter: Gigabyte GC-WB867D-I 802.11a/b/g/n/ac PCI-Express x1 Wi-Fi Adapter (£28.90 @ Amazon UK)
Total: £643.89