I see a new version of the CS 727 is out, is it possible to fit in an FMC that displays in the virtual cockpit instead of the INS?

You can use a pop-up.  I've integrated the ISG panels FMS suite; works well enough. If you search for "captain sim 727 isg panels" you'll learn more, but a number of links point you toward the Captain SIm forums which appear down right now