No, Widnows 8.1 is generally better performance-wise for gaming. Windows 7 Ultimate is a waste for gaming.
And good guess on the monitor lol It just happened to fit the budget. Dual 780s on 3x1080p monitors will give you 50+ fps with high/ultra details in everything, and looks freaking awesome doing it lol
I don't want to see a $2,200 budget go into a single 1080p screen for gaming, you won't get the joy out of it
lol