I had recently similar problems with a SuSE 9.0 based system
but this is now at least functional, using the NVIDIA-module.
You are correct that sax will not work with neither nv
(black screen) nor NVIDIA (white screen). So use
sax2 -m 0=vesa
That makes it possible to set up all aspects except possibly graphics.
You will probably not be able to test your monitor settings so save
and leave at that stage (accepting the identification 0x0342).
You may have to edit XF86Config manually.
Check if your nvidia.o-module has been properly installed in .../kernel/drivers/video etc.
This is what I did. The performance is not stellar, not much better
than what my standard geforce2ultra card delivers.