as far as I can see nVidia only supplies proprietary drivers for X86_32 and X86_64 and since you are running on a Sparc you are out of luck for that card.
You may be able to get it working with the vesa
driver or xserver-xorg-video-nv
but that's probably about it. Not sure what is available in Aurora Sparc64 but I would think either of those drivers should be there.