re: I'm ready to step up my home theater audio system.....

This second photo is of the theater room prior to my purchasing the house and repainting the walls (the previous owner had painted the room the same color as his high school kid's school's colors). I'm posting it because I wanted to give y'all the rear view of the layout of the room. I was thinking of installing 4-6 of the in-ceiling speakers in the angled ceiling and using just those speakers as my surround & atmos speakers. Would that be recommended, or will I still need to have ear level speakers installed in the walls?