Yes, you can do that, simply put both cards in and plug the monitors into each card. You'll need to install the drivers for both cards and setup the monitors orientation, so that when you move the cursor from on to the other it makes sense. Then you can set a GPU for gaming....it's all in the NVidia control panel.
I assume you know that you can't make the 2 cards work as one, in SLI, as that requires 2 identical GPUs.