Are you trying to stretch CSS onto more than one monitor? If you plan to do an even amount of monitors it wont work, if you get three though, it will probably be WAY to laggy to game, or at least you would only get maybe 10 fps. I would rather just take the single output of your pci-e card and get a vga trippler/divider. That way you get three monitors and can game without lag. Although when not in game it will not work very well.
If you plan to do the pci root, I would suggest at least a 5200.