Gamers using multi screen setups don't usually use 2 screens, its normally 3, and if you have nvidia then its 3 only (no more, no less)
You do realize you're posting to a projector subforum? We're talking multi-projector, not multi-screen. That is only relevant to using NVIDIA Surround. If the hardware solution they have splits the signal like a DH2G and adds in edge blending it'll work just fine on any NVIDIA or AMD card. Also, the 2 screen vs 3 screen relevance is gone when there are no bezels to interfere. Dual or triple projector are both good for surround gaming.