Atmos Streaming Content

Yes, you can use Plex

Is there any easy search for all of the streaming services at once?

Good question. If you use Vudu for movies the format is prominently displayed, Amazon and Netflix you have to look for the logo.

A workaround is to use an X-Box for your streaming services. You can set it to Atmos and it has a renderer that will stream everything in atmos, whether it is a native mix or not. The other night I watched a Star Trek movie that was available in dolby 5.1 through amazon video. Set the x-box to atmos and watched it in atmos, much better!