All right so I updated my build to this:
AMD Athlon II X4 760K 3.8GHz Quad-Core Processor £58.00
MSI FM2-A75MA-E35 Micro ATX FM2 Motherboard £42.11
Corsair Vengeance 4GB (2 x 2GB) DDR3-1600 Memory £38.88
Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive £43.94
Asus Radeon HD 7790 1GB Video Card £90.78
Cooler Master N200 MicroATX Mid Tower Case £33.41
Corsair CX 430W 80+ Bronze Certified Semi-Modular ATX Power Supply £36.79
Total = £343.91
I decided for the 4gb RAM because i will be upgrading regularly and my psu because it's semi-modular.
EDIT: I chose your case instead of mine