If I need just a couple outputs, I'll let SONAR create the first one, then clone it, and change name and input assignment of the clone. If I need more than a couple, I'll let SONAR create all of them, and then whack what I don't want. Although somewhat pointless, it probably actually takes fewer clicks than individually selecting a specific number of outputs when inserting the VSTi. And you can let SONAR create a track folder for you as well.
If you want more automation, you should spend some time creating custom Track Templates with associated VSTis and specific outputs and track names already set up.