Hi
You would normally just configure snapmirror or snapvault but you could configure both if you were backing up something that had bith snapmirror and snapvault components.
In your case it sounds like you would move volumes to snapmirror pane and leave snapvault blank since it isnt used.
One thing to keep in mind unlike protection manager SC will not create snapvault or snapmirror relationships. They need to exist and the gui will check and if no relationships are found you get an error.
Regards,
Keith