Interesting thread. Pioneerisloud and Snackcharmed are giving very sound advice. You think a system sounds great, and it may, until you hear a different setup and didn't realize how much sound you were missing before. If you are willing to spend some cash to upgrade to recommendations given, you would be blown away. Room acoustics and speaker placement can make a huge difference also. I also have a large room that was converted from a two car garage. I have a simple Klipsch Pro Media 2.1 hooked up yo a Schiit Modi/Magni stack that I always thought sounded very good for what it is a large room. I also have a Yamaha receiver that I bought with some inexpensive Polk surround speakers that wasn't as crisp as the small Klipsch. Last May my daughter and son in law bought a new house that has in wall speakers for surround sound and my son in law let me use his Paradigm tower speakers and 15" Velodyne sub. Man what a setup, hear sounds in the music I never knew was there.
Love to see the Ping Pong table! Avid players here.
If that setup was mine, I would hang both of the rear speakers from the "hood" behind you equal distance apart compared to the chair. that way you will get a decent surround set up. Enjoy the audio journey, it can be a rabbit hole
Heres a few pics of mine. I cant get them to be right side up no matter configuration in folder.