Overclocking Intel Core 2 Duo E6400 Conroe 2.13GHz, which heatsink to buy?

[pepsiclock]

I plan on overclocking my Intel Core 2 Duo E6400 Conroe ( http://www.newegg.com/Product/Produc...82E16819115004 )but I am unsure of which heatsink to buy. I know I want a zalman but please someone help me decide which would be the smartest choice purchase.
These are the heatsinks I'm looking at currently
http://www.newegg.com/Product/Produc...alman%2b9700NT
http://www.newegg.com/Product/Produc...82E16835118019
http://www.newegg.com/Product/Produc...82E16835118223
Keep in mind I don't care about the price but quality. I am right now leaning towards the Zalman CNPS 9700 NT 110mm 2 Ball Ultra Quiet CPU Cooler. I'd also appreciate any other suggestions of heatsinks that you guys have experience with.
Also if anyone has any websites with tutorials on how to overclock I'd appreciate it if you could post them here aswell. To my understanding you overclock thru the BIOS and each BIOS is different so would the procedure of overclocking vary a lot? If it matters I have an ASUS P5B Deluxe Mobo. I've never overclocked anything and any tips plus tutorials would really help me out. Thanks for reading the post and thank you to any help posted.

[EXreaction]

The only difference between the 9700 NT and 9700 LED models seems to be that the NT has a quieter fan, and it has a 4 pin fan connector, but the LED model has an added fan speed controller, though I wouldn't use it and connect it to the motherboard instead.