Which is better for cooling?

Hi,

Looking at overclocking an opteron chip, and I currently have a Vapochill Micro Extreme Performance:

http://www.vapochill.com/main/page.asp?sideid=727

However I was half considering getting a Swifttech cooler a la this one:

http://www.swiftnets.com/products/mcx6400-V.asp

with a nice ultra quiet silenx fan on it, all of which I can pick up for just about £20 (2nd hand).

I haven't had a chance to test the vapochill yet but don't wanna miss out on the swifttech if its a far better cooler, as I am gonna be looking at doing some serious overclocking. SO which is the better actual cooler, performance wise? Will the vapochill suffice or is it not really an overclockers cpu cooler?

If it matters, the spec for the comp is:

Opty 144
Asrock Dual SATA2 939 mobo
1gb OCZ EL DDR 3500 ram
HIS ICEII Turbo x800xl

Cheers!

edit: or another option is the Thermaltake Big Typhoon, again for £20:

http://www.thermaltake.com/product/c...4/cl-p0114.asp

So are either of the two I don't have worth the £20 money it'll cost for them, or will the difference be negligible?