Go for a pair of GTX 460's then.
Less money, and better performance.
Or get one GTX 460, that should run you about $210 or $250(overclocked version).
That should be able to run any game out there in 3d at 1080p fine.
Well except SE's new killer title FFXIV. Im getting myself a pair of GTX 460's. Hope that will be enough!