I know SAV is EOL but you can still download defs from here (JDB file):
http://www.symantec.com/security_response/definitions/download/detail.jsp?gid=savce
End of Life announcement for Symantec AntiVirus Corporate Edition and Symantec Client Security
http://www.symantec.com/docs/TECH178551
You can install SEP 11.x on these machines, although 11.x has started the EOL process as well....
http://www.symantec.com/docs/TECH207274
In summary per Symantec:
Symantec AntiVirus 10.x Corporate Edition (SAV) will reach its scheduled End-of-Support-Life (EOSL) on July 4, 2012. Virus definitions, maintenance updates, and technical support will no longer be available for this product. The recommended upgrade path is to replace SAV 10.x with Symantec Endpoint Protection 12.1 (SEP 12.1).
Info on each release here as well:
http://www.symantec.com/business/support/index?page=releasedetails&key=51852#