Your card should run fine with the latest drivers so if you already added Livna.
yum install kmod-nvidia -y
Should be all you need.
Now as for the multiple monitor deal, sorry I can't be of much help there, Twinview should make it easier though.
from a terminal after the reboot or
BTW remember to back up your working /etc/X11/xorg.conf between changes so that you can recover easily and quickly should something go wrong.