That's a well set up room and looks well planned.
Did a ton of research myself on equipment placement (see my systems page).
Several generalities apply:
Each room and speaker set up is unique and no specific set up is best in all cases.
Most speakers sound better away from room boundaries.
Source and amp equipment is best placed along side walls or on floor behind speakers.
Listening position in the room is possibly the most important factor and is dictated by bass room modes. The smoothest and best bass determines the listening spot.
Adjust initial speaker position partly based on listening position and partly on bass smoothness.
Use toe and tilt and fine movements of the speaker to "lock in" imaging.
The smaller the room the greater the challenges.
One of the best systems I've ever heard was at Jeff Catalano's flat (High Water Sound). In that system, the speakers were positioned along the short wall in a room approximately 50 feet long by 16 feet wide by 14 feet high. The speakers were approximately 8 feet center to center apart, about 15 feet from front wall and about 12 or more feet to the listening position. I estimate that the listening spot was 35% or so into the room from the back wall. Of note, other than about 20,000 lp's (not kidding) flanking both side walls floor to ceiling, and 2-foot deep beams along the length of said ceiling, no room treatments were in use.
Of note Jeff's rooms are typically the best or among the best at shows worldwide, so the guy knows what he's doing. Study some photos from his set ups (google) for tips/hints.
The Jim Smith book also a great resource.