Just incase u hav'nt ordered anything yet
Memory:
http://www.overclockers.co.uk/showproduct.php?prodid=MY-205-CS&groupid=701&catid=8&subcat=1389
Cooler:
http://www.overclockers.co.uk/showproduct.php?prodid=HS-011-NC&groupid=701&catid=57&subcat=1395
Memory is more then fine, and is compatable with the above cooler, and with the above cooler you will comfortably hit 4-4.2ghz depending on voltages needed.
Also, when you want to try overclocking, just drop by in the overclocking and cooling section, many of us will gladly help you along.
i did actually buy yesterday straight after i posted in the graphics board. many thanks for your comments and it's nice to know there are experts there to show me how to overclock without screwing it up. i might just give it a try.