I would get this:
Intel Core i7-2600K 3.40GHz (Sandybridge) Socket LGA1155 Processor with FREE Lost Planet 2 PC Game - Retail £266.99
(£222.49) £266.99
Gigabyte P67A-UD3 Intel P67 Chipset (Socket 1155) DDR3 Motherboard - (Sandybridge) £99.98
(£83.32) £99.98
OCZ Vertex 2 "25nm Edition" 50GB 2.5" SATA-II Solid State Hard Drive (OCZSSD2-2VTX50G) £88.79
(£73.99) £88.79
G.Skill RipJaw 8GB (2x4GB) DDR3 PC3-10666C9 1333MHz Dual Channel Kit £83.99
(£69.99) £83.99
HIS ATI Radeon HD 5750 iCooler IV 512MB GDDR5 PCI-Express Graphics Card (H575FN512) £83.99
(£69.99) £83.99
Corsair Builder Series CX 600W ATX Power Supply (CMPSU-600CXUK) £58.99
(£49.16) £58.99
Samsung SpinPoint F3 1TB SATA-II 32MB Cache - OEM (HD103SJ) £40.99
(£34.16) £40.99
Coolermaster Elite 334 Midi Case - Black £33.68
(£28.07) £33.68
Gelid Tranquillo CPU Cooler (Socket 754/939/940/AM2/AM2+/AM3/LGA775/LGA1155/LGA1156/LGA1366) £26.53
(£22.11) £26.53
OcUK 22x DVD±RW SATA ReWriter (Black) - OEM £11.99
(£9.99) £11.99
Sub Total : £663.27
Shipping cost assumes delivery to UK Mainland with:
DPD Next Day Parcel
(This can be changed during checkout) Shipping : £12.50
VAT is being charged at 20.00% VAT : £135.15
Total : £810.92
Okay, so its £10 over, but 8GB of RAM, 64GB SSD (with faster read and write than the C300) overclockable, quieter cooler - yes, graphics card is worse, but more than adequate for your uses (and a spot of gaming on the side

)