For high overclocks, you should go for the 965P chipset. Such as the Gigabyte 965P-DS3, or ASUS P5B Deluxe. But the new 650i, chipsets aren't bad. They get high overclocks, too. And for that, I suggest the MSI P6N Plat or SLI-FI. You do know, that you will, also have to get DDR2 ram, right?