I agree ksw, that a chiller's effect is questionable, since the only thing a rad would do is try to bring temperatures down to ambiant, nothing less.
A chiller could be used though, to help the rad in its purpose.
It's been done before here:
http://www.overclex.net/content.php3...D43%26page%3D1
I've got some more math to do. I'll use some of these numbers:
http://www.aquatictech.com/chillers.html
and let ya'll know what I come up with.