PCI video card to play Never Winter Nights 2

No it will not.

The very best that card will do is probably 10 - 20 FPS at the lowest settings possible. I played NW2 through and it was pretty demanding even for my HD 3870 and q6600 at 3 GHz. I know the 3870 isn't the best, but it's still a pretty good card.

If I remember correctly, I played with all High settings, 2x AA and linear AF and had a playable frame rate with a rare lag.

According to wikipedia Geforce 8 series supports Pixel Shader 4.0

*Technically* I am sure you could play the game with that card, it is a recent enough generation to support things like pixel shader. The only real issue is if the game will get a playable frame rate.

http://en.wikipedia.org/wiki/Pixel_shader

that is at 4xAA,16x AF @1280x1024

he will be at 0xAA, 0xAF @ 1024x768, med/low settings.

Well it might run the game at 800*600 with 12-15fps with low settings, that's not what I call playable fps for that type of game...

Well the 8400GS Pci-E MIGHT get @ 1024*768 medium setting:
Max fps: 30
Low fps: 10
Avg fps: 16
Those number are speculation only if compare to other games like Farcry2 and oblivion.

And the regular PCI version will be a little slower.