You don't look like you need much help.
You could save some by getting the Asus P6X58D-E instead of the premium, as most people don't need the features that the Premium has, and the Premium wouldn't be noticeably better than the -E in OCing either.
I agree that the Prolimatech Megahalems is the better choice for a heatsink.
According to this chart
the Scythe S-Flex 1200RPM fan gets a bit more airflow compared to the Gentle Typhoon you listed, while being quieter. Seeing as it's going on your CPU which you plan to OC I'd suggest getting the 1600RPM S-Flex, as it is still very quiet, but produces a bit more airflow which would likely be beneficial in keeping temps down.