If I'm not mistaken, '91 is when the hubs were changed. Then the spindles changed in '93. I do not believe that the hubs changed again in '93, but I could be mistaken.
So, to the best of my knowledge, standard rotors for '93 and up should work on your '92. However, sport rotors won't work unless you go with the '93 and up spindles. The sport rotors are the same size as the M8 rotors, but won't fit under the older spindles.