Newbie - e6600 replacement heatsink question

I have read the sticky regarding overclocking core duo 2 and the replacement HSF.

I have a P5B ASUS motherboard with a e6600 Core 2 Duo. Now fitting the Intel HSF was a nightmare, it took me ages to get the HSF to pop into the motherboard and I am still not convinced it is 100% correctly fitted.
After speaking to some friends and reading posts here, I think it might be worth purchasing a better HSF - especially as I do want to overclock at some point.

Out of the ones listed, can someone advise which would suite me? The other problem I have is finding places that sell these HSF, I have found the Typhoon and one that would suite my Antec SLK3000B case as it has an CPU chassis air guide.

Thanks in advance for any help.