Ok had a play around and took on board the suggestions so far. Came up with this build. What do you think?
No doubt my choice of case will go down like a lead balloon

but ive read up a bit on that case and for the price the build quality and cooling etc seem to deliver a bang for your buck so to speak.
MSI GeForce GTX 570 1280MB GDDR5 PCI-Express Graphics Card £251.99
£251.99
Intel Core i5-2500K 3.30GHz (Sandybridge) Socket LGA1155 Processor - OEM £161.99
Asus P8Z68-M PRO Intel Z68 (Socket 1155) DDR3 Motherboard £109.99
£109.99
Corsair Enthusiast Series TX 750W V2 High Performance '80 Plus Bronze' Power Supply (CMPSU-750TXV2UK) £92.99
£92.99
Seagate Barracuda 7200.12 500GB SATA 6Gb/s 16MB Cache - OEM (ST500DM002) £89.99
Microsoft Windows 7 Home Premium SP1 64-Bit - OEM (GFC-02050) £79.99
£79.99
OCZ Agility 3 60GB 2.5" SATA-3 Solid State Hard Drive (AGT3-25SAT3-60G) £78.98
£78.98
Zalman Z9 Plus Tower Case with Fan Controller - Black £49.99
£49.99
Kingston HyperX Genesis Grey 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit (KHX1600C9D3X2K2/8GX) £47.99
£47.99
Gelid Tranquillo CPU Cooler (Socket 754/939/940/AM2/AM2+/AM3/LGA775/LGA1155/LGA1156/LGA1366) £25.99
£25.99
Samsung SH-S222AB/RSMS 22x DVD±RW SATA ReWriter (Black/Silver/Biege) - Retail £19.99
Sub Total : £841.57
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 : £170.81
Total : £1,024.88