Hi I want to run a second display on my mac pro, that currently only has one NVIDIA GeForce GT 120. (it only has one DVI port). Can I buy any graphics card that has a PCI Express 2.0 interface and install it in the mac pro without any issues? Is there anything else in the tech specs I need to make sure it does/doesn't have in order for it to work in the mac pro? Appreciate any advice!