It is unfortunate that they are no longer on that campus.
I recommend contacting the university to see if they have any records of ANYTHING pertaining to the organization or some of the members whose names you remember.
I assume it was a local so there wouldn't be a larger entity to contact. (There's another Sigma Phi Nu that was founded in 1996)
"Men are from Earth, women are from Earth. Deal with it."
~ George Carlin
"Don't believe everyone's story. Always know different sides of the story. You will be surprised."