LePaul, my first reply and Skuzzy's reply answers your question...
the answer is, with those video cards you have, 2 monitors will work, 3 will not. the information in that nvidia link i posted is specific about it.
get yourself a triplehead2go adaptor and connect 3 monitors to it, then connect it to the appropriate display port(s) on one card and you should be able to run 3 monitors off one card and get results you're wanting.