Black & Red/Black & Blue Budget build

  Hey, my friends building either a black and red or Black and blue £700 Budget Build (Including OS) He will be overclocking, for the Black and red he wanted an AMD 7950, Black and Blue a MSI twin frozr 660 ti........(both builds with an i5,2500k OR 3570k, what are the differences,pros and cons?)

Heres what i came up with for the Msi build:

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor (£163.19 @ Aria PC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler (£25.45 @ Scan.co.uk)
Motherboard: MSI Z77A-G41 ATX LGA1155 Motherboard (£62.99 @ Novatech)
Memory: Corsair XMS3 8GB (2 x 4GB) DDR3-1600 Memory (£32.99 @ Amazon UK)
Storage: Seagate Constellation ES 1TB 3.5" 7200RPM Internal Hard Drive (£46.74 @ Aria PC)
Video Card: MSI GeForce GTX 660 Ti 2GB Video Card (£215.59 @ Scan.co.uk)
Case: Silverstone SST-RL01B-USB 3.0 (Black) ATX Mid Tower Case (£35.16 @ Scan.co.uk)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply (£47.99 @ Aria PC)
Optical Drive: Lite-On iHAS124-04 DVD/CD Writer (£11.40 @ Aria PC)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) (£65.99 @ Aria PC)
Total: £707.49
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-02-10 12:43 GMT+0000)

Thanks for reading, i hope you can help my friend in need