I don't use SuSE myself but I know that even the newest XFree (4.20) only supports up to GeForce 3
So Sax which somehow reads these datas somehow only shows you a GeForce 3 as well.
What you want to do is to simply select the GeForce 3 and go on
When you are done configuring, save the config file and open it in a text editor.
Search for a line saying
in the "Device" section
Simply replace the nv with nvidia
If you installed the two nvidia packages correctly it should work out
You still have to remove a few line that might still be in the XFree Config but that is described in the documentation of the packages (/usr/share/doc/NVIDIA_GLX-1.0/README)
That sould work