Nividia cards love being water cooled!
EK GeForce 470 GTX VGA Liquid Cooling Block - Nickel + Acetal (EK-FC470 GTX-Nickel+Acetal) Hot Item! - FrozenCPU.com
newegg has some water cooling stuff
frozenCPU is good, sidewindercomputers is good
edit: taking cooler off 470
hmm after seeing Slaymates build i thought how does 2 470's compare to a single 5970.
and per this website: http://www.guru3d.com/article/geforc...-sli-review/13
GTX 470's in SLI score almost identicle to a single 5970... and 2 470's cost almost identicle as much as a 5970... with that in mind, i would go witha 5970 over 2 470's because down the road when you want more oomph out of your computer, if you have 2 video cards already, that wont let you add another one, where as if yu have a sinle 5970, and 2 years down the road, you want more out and a 5970 cost ( lets say ) $300, you can pick up another one and toss it in there and you will be good to go for another long while...
so in my oppinion, i would change SLI 470's to a 5970. plus its easier to water cool a single card ( and less expensive ) then a 2 cards.