Best approach to integrate multiplayer in existing Unity Project

Hey guys,

So the title is the main focus, I have a project in the store and currently we only have singleplayer with bots but, I'm looking to add a multiplayer in it, what is the best framework/ easiest to use on unity, I've heard there's the standard Unet and Photon as well. I have been reading into Rooms with oculus and from my understanding I would need that to allow my user to be able to talk in game. SO what's your guys opinions on the easiest and best framework to use to integrate multiplayer for my GearVR project and have the ability to talk in game? (using Unity 5.6.4 if that matters)

Thanks