A room that size, all you need is SONOS Bar on wall and SONOS Sub. Why clutter the space with bulky speakers/electronics. I have been using a SONOS soundbar / sub (3.1) for 10 plus years in a similar space for movies and music. Never felt the need to upgrade or anything else. Sonos Truplay software optimizes the sound to the nth degree. A well integrated sub makes all the difference, bass to music is like meat on the bones. Once you got it dialed in you won’t be able localize the bass.
SONOS is not cheap but everything else in their price range or lower pales in comparison.