Go for the Zotac GTX 480 Amp! Edition - it runs a lot cooler, as in 20°C or more compared to nVidia's reference cooler (~50°C 3DMark, peak temperature) - the Zotac Amp! has a triple slot Zalman VF3000 cooler which may make SLI a bit more difficult depending on your board.
Costs the same as the EVGA after rebate - the Zotac has a limited lifetime warranty just like EVGA's, and just like EVGA you need to sign up and register the product within 30 days otherwise it'll only be a two year warranty.
Definitely get a EVGA card, the Superclocked + is the one to get, includes the high flow bracket and the backplate.
And 5970 is NOT good for longterm. Dual cards are just about always terrible and a waste of money, and you're already limiting yourself as far as future upgrades go. I wouldn't CF 2 5970s, cause they scale terribly, the the 480s in SLI are beast machines.
hmmmm so many choices! Once again Lmeow's got it dead on.
Not sure I want to spend the 1k on two of these Zotacs though. Seems like 500 for 2 460s and waiting for the next best thing to come out would be best...