Hello,
In your case, you would like to Optimize Client Install Packages and you want to install a AV Only Client Install Package and would have disabled the SONAR Content downloads as SONAR is disabled.
You would have create a package with Basic Content with only AV/AS feature, this would help in lowering down the package size and would save on bandwidth.
I would suggest you to follow these Articles:
How to export Symantec Endpoint Protection (SEP) client install packages without any definitions or package with Basic Content.
http://www.symantec.com/docs/TECH178698
and
Creating custom client installation packages in the Symantec Endpoint Protection Manager console version 12.1
http://www.symantec.com/docs/TECH165801
and
Upgrade clients to SEP 12.1 by Auto upgrade feature
https://www-secure.symantec.com/connect/articles/upgrade-clients-sep-121-auto-upgrade-feature
I also have a feeling that you are in planning stage and would like you give a check on these Article as well -
Planning the installation http://www.symantec.com/docs/HOWTO55061
Network architecture considerations http://www.symantec.com/docs/HOWTO55114
Getting up and running on Symantec Endpoint Protection for the first time
http://www.symantec.com/docs/HOWTO55274
Hope that helps!!