bshaw0,

I don't know if you have done any searching for sy77 voices on the internet but there are a few sites out there with some. In addition, there is a "Strings" wave card for the SY77 that may have what you're looking for. You can't find these in stores anymore but they show up on EBAY all the time. Also, go to this site...
http://boardserver.mycomputer.com/list.html?u=mfbuisman&f=1

and ask the same question. It is a forum just for the SY77. There is a link at the top of the page to go to the main SY77 page. The webmaster has available voices on the internet (probably all of them) in one file for download.

Good luck