Any of the ss1, ss1+, or ss2 (with a small file) will fit in your 3/80 (campus)
chassis.  You might consider an "upgrade" from one of the parts supplier
such as West Coast Computer Exchange.  You can find their addresses in the back
of the various UNIX mags like SunWorld or Advanced Systems.

Otherwise, I run SunOS 4.1.1_u1 on my 3/60 at home and like it very well.
-sam