oh right, im obviously not very familiar with overclocking

ah, i get you now, 2 front fans aren't included, i'll certainly think about buying extra ones - thanks very much for the clear help
here are my finalized specs - do they look alright?
Intel Core i7 920 D0 Stepping (SLBEJ) 2.66Ghz (Nehalem) (Socket LGA1366) - Retail + World In Conflict PC Game £212.98
Asus P6T Intel X58 (Socket 1366) PCI-Express DDR3 Motherboard Asus P6T Intel X58 (Socket 1366) PCI-Express DDR3 Motherboard 169.99
XFX ATI Radeon HD 4890 XT 1GB GDDR5 PCI-Express Graphics Card - Inc. Tom Clancy's H.A.W.X. 140.99
Patriot Viper 6GB (3x2GB) DDR3 PC3-12800 (1600MHz) Low Latency Tri-Channel (PVT36G1600LLK) Patriot Viper 6GB (3x2GB) DDR3 PC3-12800 (1600MHz) Low Latency Tri-Channel (PVT36G1600LLK) 68.99
OCZ ModXStream Pro 600w Silent SLI Ready ATX2 Modular Power Supply OCZ ModXStream Pro 600w Silent SLI Ready ATX2 Modular Power Supply 54.99
Antec 300 Three Hundred Ultimate Gaming Case - Black (No PSU) Antec 300 Three Hundred Ultimate Gaming Case - Black (No PSU) 44.99
Seagate Barracuda 7200.12 500GB SATA-II 16MB Cache - OEM (ST3500418AS) Seagate Barracuda 7200.12 500GB SATA-II 16MB Cache - OEM* 38.99
Akasa AK-967 Nero Direct Contact Heatpipe CPU Cooler (AM2/AM2+/939/LGA775/LGA1366) Akasa AK-967 Nero Direct Contact Heatpipe CPU Cooler (AM2/AM2+/939/LGA775/LGA1366)* 23.99
Scythe Kaze Jyuni 1200RPM Slipstream 120mm Fan 6.89
Scythe Kaze Jyuni 1200RPM Slipstream 120mm Fan 6.89
Acer 24" widescreen V243HBD off ****.com 147.74