http://lowendmac.com/video/index.html
The above link should have the information you are looking for. Very few Nubus cards do 1280x1024 or better, most high end ones do 24 bit at 1024x768 and 1152x870. I have a Supermac Thunder II GX 1600 that is supposed to do 1600x1200 @ 24 bit if I can find the correct 13w3 cable to use it (not sure about refresh rates either).
The above link should have the information you are looking for. Very few Nubus cards do 1280x1024 or better, most high end ones do 24 bit at 1024x768 and 1152x870. I have a Supermac Thunder II GX 1600 that is supposed to do 1600x1200 @ 24 bit if I can find the correct 13w3 cable to use it (not sure about refresh rates either).