Currently TestTrack and Surround SCM only support silent installation of the client components. Some companies want to script the client installation because they have many client machines, but scripting the server would be less used by most companies as they generally only have a single server. We have not had customer requests for a server version of the silent installer, but I have entered your suggestion as a feature request for future consideration.
BTW, both TestTrack and Surround SCM have a built-in automatic client install option. If this option is enabled, when older client applications connect to the server the user is prompted with an option to upgrade their client application. There are still reasons that some companies prefer to script the installation, but I wanted to make sure you were aware of the automatic client install option, which you can read about in the online help.