Could you also potentially use the Facebook Groups functionality? That way you’d have everyone connected via Facebook, and be able to use all the Facebook features (posting, commenting, liking and sharing), and it would allow the group to be discoverable also (depending on the privacy settings you choose).
You could then also create a facebook messenger group as well for everyone to message each other if you want a different format.
It really depends on what you’re trying to achieve as your overall objective.
I hope this helps~