From reading many reviews of heat sinks, it seems the best for overclocking are the following:
these are pretty expensive... the SK6 is the cheapest. you might be able to use a cheaper model of the Swiftech, like the MCXC370 (copper base) or MCX370 (aluminum base).
oh ya, and they usually upgrade the fan to a high cfm delta
<font color=purple>"Brilliant thinkers have often met violent opposition from mediocre minds."