I'm not too sure what the question is but i'd like to point out that you would only need one additional card with two outputs. Most cards now-days have 2-dvi or 1 dvi/1 vga out so you will be covered.
I'm pretty sure all modern windows support multi displays but i'm not sure Pinnacle 12 does. (maybe it does, i don't know).
Hope it helps, feel free to ask more questions.