Watch your tongue mate, don't go around insulting my GTS.
And no, you can't SLI a 8800GTS to a GTX295. It works for 8800GT + 8800GTS 512 because they have the same core (G92). The only difference between the 2 is that the GT has part of the core disabled giving it a lower shader count.
2 x 295? If you want to throw cash around, just send it my way.
At the moment, even GTX 275 is overkill for most games. Then there's the 285 and the dual-GPU 295 (2x285). Just get 1 295 for now, and another in the future when you maybe actually need it, a heck of a lot cheaper.
If it's performance you're after, 2x 275 in SLI beats a single 295 (for less cost), I can only guess how retardedly fast 2x 285 is.
Ow, and DX11 lies ahead. You sure you want to waste that kinda cash on 2 monsters that don't even support DX10.1?