Need help setting up multiplayer

I have both a Vive and Rift and want to play both online multiplayer and coop games. What setup is required to do that?

All of the Vive games I play through Steam. Should I start a separate Steam account and run the Rift through that or should I play it through the Oculus store? Also, are there issues playing online together behind the same router.

Finally, any good suggestions on good coop games? I have Arizona Sunshine that I know can be played coop but any other good ones? Thanks, Jason.