If you are having trouble setting up with 2 graphics cards, you can look into buying display cards that support multiple monitors. They are much easier setting up and running. For example Matrox has graphic cards that can connect 2 displays and their drivers make the installation fairly easy. I am sure there are other manufactors too.
One thing I can tell you, once you have a computer with 2 displays and get used to working with them you will never go back to a single display computer.
rcparur got a reaction from XRumerTest in How To Connect Dual/triple Monitor + Advantages Guide on how to install mult. monitors