i've decided it is worth it. a 1ghz overclock just sounds better than 800mhz.
i'm getting max load temps of 70c with this el cheapo cooler
http://www.overclockers.co.uk/showproduct.php?prodid=HS-041-AK
only thing i could find locally that was quad capable.
70C sounds fine. It's only ever going to get that high when priming or playing on Crysis for hours and hours