800 pound gaming rig

I have already put something together just want to hear opinions and suggestions or a simple thats good. it goes a little over my budget but its not that bad

NZXT Vulcan Micro ATX Black Case - No Psu £54.95
Intel Core i5 2500K 3.3GHz Socket 1155 6MB Cache Retail Boxed Processor £170.98
HIS HD 6950 IceQ X 2GB GDDR5 Dual DVI Dual Mini DisplayPort HDMI PCI-E Graphics Card £205.00
G-Skill 8GB (2x4GB) DDR3 1600Mhz RipjawsX Memory Kit CL9 (9-9-9-24) 1.5V £36.83
Antec TruePower New 650W Modular PSU £65.99
Arctic Cooling Freezer 7 Pro rev 2 Socket Heatpipe CPU Cooler £15.98
Samsung S22A300H LCD LED Full HD 21.5" HDMI Monitor £104.98
Seagate 500GB 3.5" SATA-III 6Gb/s Barracuda Hard Drive 7200RPM 16MB Cache £74.99
Asus Maximus IV Gene-Z Z68 Socket 1155 8 Channel HD Audio mATX Motherboard £147.94

i plan on unlocking the 6950 to the 6970, also OCing might be something i want to consider

I've had an Artic Cooling Freezer Pro 7, they're terrible. Barely any difference from stock. (although this was using an AMD stock cooler, dunno about intel.)
You sure on getting an mATX case and mobo? i would always go for an ATX one, more space, better heat transfer.