You want them in SLI?
SLI means using both cards to power 1 monitor for games, meaning more perfoemance, if you want to use 2 monitors then you dont have to have SLI enabled.
SLI is when 2 graphics cards (PCI-Express) are connected using a special bridge (should come with cards) to connect the two together, you can then enable SLI when you want to play games so that you get more power, you can use 2 monitors and then engage SLI (so one monitor shuts off) just for games.