We are building a new house, and I would like to equip the living/dining/kitchen area with Sonos ceiling speakers and Sonos TV audio. I’m new to Sonos equipment, so I’m still learning how this might work.

The room measures 31 feet x 30 feet, with a vaulted ceiling that is 9 feet at the walls and 11’-6” at the peak.

There will be a lot of hard surfaces -- kitchen counters and cabinets, large glass doors, hard-surface floors with rugs -- so I’m not expecting perfection, just hoping for a decent listening experience.

Our goals are to have TV sound come through the ceiling speakers when watching TV programs while working in the kitchen/dining area; have music available through ceiling speakers in the great room area when not watching TV; and have a surround system (or at least a soundbar and sub) in the TV area for dedicated TV viewing.

After reading a number of forum posts, I think that a setup along these lines could work:

• Four wired 8” Sonos Architectural in-ceiling speakers, two above the kitchen/dining area and two in the middle of the great room. 
• Individual volume controls for each pair of in-ceiling speakers
• An Amp to drive the ceiling speakers in mono mode
• An Arc soundbar and Gen 3 sub for the TV
• Two Era 100s on stands behind TV seating for the rear channels, if we decide we want full surround sound

Questions:

• Will the single Amp work in this setup, or do I need two?
• Is there a risk of the TV sound in the ceiling speakers being out of sync with the TV? I’ve seen this mentioned in some posts, but I think they were several years old.
• I didn’t include a third pair of in-ceiling speakers closer to the fireplace/TV wall because I figure that the TV sound from the Arc soundbar/sub/100s will be sufficient for anyone close to the TV when it’s in use, and people listening to music when the TV is off are not likely to be in that part of the room. Does this sound reasonable, or is there a chance that I’ll regret not adding the third pair given the large room and high ceiling?
• Is there anything that’s missing or that you’d do differently?

Thanks very much for any insight and guidance you can offer. I really appreciate it!