Bad choice for the processor. The X3 720 has an unlocked multiplier meaning that it will be much easier to overclock. The X3 710 has a locked multiplier. The 780G it a better chipset than the 8200 IMHO and also I have not seen much about the overclocking capabilities of the 8200.
The HD4870 is £8 cheaper at Novatech who are a good company:
http://www.novatech.co.uk/novatech/s....html?SAP-4870
They have free postage too!
Vista Home Basic is £3 cheaper at Scan:
http://www.scan.co.uk/Products/Micro...t-1Pk-OEM-(DVD)
The 320gb Samsung F1 is on Today Only for £37.94!
There are some 120mm fans on Today Only too.