For a start don't buy OEM windows 7 you will regret it, buy retail.
The artic freezer 7 pro is NOT good enough to overclock an i7 much.
If you need to keep £££ down, get an i5 and clock it, as an unclocked i7 is really a waste of money as they are high end and espensive. Also you have a monster cpu with an average airflow case and poor graphics (compared to the power of the i7).
I'd say get win7 home retail, a 5850, and a good cpu cooler for an i5 setup.