About deployment on 50 Server and 50 Desktops, If you are planing to use Migration and Deployment Wizard it is by default configured to Push Package on 10 computers at one time(This can be changed). So if you select 50 computers it would do 10 at a time and then start picking up from rest.
In case of Local Area Connection it hardly takes a minute to push the package to a computer. Once the package is pushed it takes around 5 to 10 mins to install it. In the installation process, If Symantec AntivirusV is installed on the computer it will uninstall it and then install Symantec Endpoint Protection. If Symantec Antivirus is not present then it would be a clean installation of Symantec Endpoint Protection.
This will be same for Server and Desktops.
Abotu the network Bandwidth, once you have the package ready you can check the size and multiply it with 10, this will be the bandwidth that will be utilized when the package is Pushed.
Can you please explain bit more about the HIPs portion, what tuning options are you looking for?