Hi there,
I strongly recommend making those Macs managed. Having them report into the SEPM means they can be assigned a consistent policy. Also: log, reports, alert and notifications can be set up and viewed so that admin will know if there is an outbreak seen on these computers, or if the Mac clients' AV definitions grow very old.
How to convert an unmanaged Symantec Endpoint Protection for Macintosh client to managed
Article URL http://www.symantec.com/docs/TECH131585
I recommend making sure that all of those Macs are running either the SEP 11 RU7 MP1 or SEP 12.1 RU2 Mac client. The SEPM cannot manage SAV 10 for Mac clients.
Also: I recommend having those 100 Macs update their definitions from an internal LiveUpdate Administrator server. This saves 100 duplicate downloads from the Internet every day.
Using the LiveUpdate Administrator 2.x to download updates for Symantec Endpoint Protection for Macintosh
Article URL http://www.symantec.com/docs/TECH103198
Hope this helps!! Please keep this thread up-to-date with your progress, or mark it solved if the advice given has answered your question.