To work with components in the installer is a good idea. Also the core components will have to be selectable if we want to have multiserver setups where not all services run on the same server.
3x Webserver (on one of this the controlpanel is installed)
2x DNS Server
1x Database Server
If we want to manage this with ISPConfig, the installer must handle these scenario.
Install Controlpanel (y/n)
Install BIND support (y/n)
Install Mailserver support (y/n)
Install DNS support(y/n)
Install Database MySQL support (y/n)
Install Database Postgres support (y/n)
What do you think?