You can’t quite use the Amp in the way you describe, not with four ceiling speakers (ignoring the audio issues with that configuration), see:

https://www.sonos.com/en-us/guides/amp

Thanks for the reply - I checked the link and didn’t gain any info on my situation.

I’m of the thought that each AMP will provide L+R speaker connections and that the soundbar connection to TV (unknown what it is at this point) will provide the audio signal.  Need to get configuration right in order to achieve surround sound……..

SONOS cannot accommodate a 3rd party sound bar.

It is a SONOS sound bar but I haven’t had a chance to determine which one 

The soundbar would be the front speakers. Depending on their placement, I doubt that it would be productive to incorporate two pairs of ceiling speakers as surrounds. You could use one AMP to drive one pair of ceiling speakers used as surrounds and use a second AMP to drive the other pair of ceiling speakers. The second AMP would not be used while watching TV, but it could be Grouped with the other speakers for music play. The 3rd AMP could be used in a separate physical room.

In SONOS lingo a “Room” is a single speaker, pair of speakers, or a surround system. Rooms can be “Grouped” to play the same music. Music will be synchronized with all speakers in a Group. There will be a slight latency for Rooms Grouped with the Surround Room while playing TV audio.

Just to drive that point as clearly as possible, Sonos does not offer a solution in which a soundbar is only the center speaker, and you have separate left and right speakers driven by an Amp. 

All Sonos soundbars have front right, front center, and front left speakers in the enclosure. They’re separate speakers, just all in the single ‘box’. One of them, the Sonos Arc, also includes upward firing speakers for Dolby Atmos use, the Beam merely interpolates that signal into the forward firing speakers. The Ray, being connected via an optical connection, is maxed out at Dolby Digital.

You can choose to use an Amp as a driver for ‘front’ speakers, but in that case you get an generated center speaker from the output of the two speakers connected, there is no way to add a physical center speaker, of either Sonos make, or third party.

As you’ve noted above, the prevailing opinion is that for home theater use, there’s some challenges in using ceiling mounted speakers, due to the mental disconnect that most people have with sound coming from above them, rather than in the same plane as their head. Your neighbor may not have that issue, but most often, when setting up both front and surround speakers, the recommendation is to have them at head height, with the soundbar under the screen, and the surrounds mounted on speaker stands or similar height wall mounts.