well for cheap and moderate to good overclock i say get the ac freezer 64 from newegg.
http://www.newegg.com/Product/Produc...82E16835185125
or the better/best option http://www.newegg.com/Product/Produc...82E16835106061
http://www.newegg.com/Product/Produc...82E16835185125
or the better/best option http://www.newegg.com/Product/Produc...82E16835106061