Welcome to AH.
You didn't mention the video part; tv/projector screen size. If fairly large, you should move your seating to about 13 feet, then you should install 7.1.4. Four speakers in the ceiling per Dolby specs. Some BlueRay do have Atmos, not all. Hard to know what the future will bring. 4K discs will have Atmos.
If you can do it, at least wire for it if you are wiring the other speaker locations.