Which leaves me asking,
What driver is used to 'get the system running',
How to build the kmods for my kernel ( 3.10.9 AFAIK)
.. Then on, sounds good.
Can I try this with my old ati card in, on one monitor,
The nVidia on the second monitor?
Get your system running -- with the card installed -- then install the correct nVidia driver. I don't know if the nVidia filed (kmods) are still available for you kernel you are running. If not, you can compile your own files from the source rpms or you can try installing the akmod file and see if it will build the correct files for you.