Where are the ceiling speakers in the room in relation to the seated TV-viewing position? 
If you ‘bond’ the Amp/Speakers to the Arc, the ceiling speakers will be in sync, but they will output the rear left/right TV surround channels only. Is that what you’re looking for here?

The idea was to have the TV centered on that wall obviously, but the contractor (My dad) installed the Fire place off center.  Was going to do wall speakers, and even side/surround speakers.

How do I connect the Sub to the Arc ?  Sub is directly connected to the AMP.

Amp 1 connected to the TV with HDMI cable going to wall.  2nd Amp is for outdoor speakers.

SVS Sub connected to AMP 1.

I created a group for watching movies. (Arc + AMP as surrounds)   Didn’t really work… volume still comes thru both and is delayed slightly.

Surrounds are not grouped.  Grouping just plays the same thing as the Arc, except a TV source will be buffered.  That is why you are hearing the delay.  Surrounds play surround effects channels, not just a repeat of the soundbar and need to be bonded to the Arc via the Add Surrounds menu in the settings for the Arc.

The two ceiling speakers seem to be above the main seating area. Anyhow, whilst I’m personally not a fan of using ceiling speakers for TV audio, you can perhaps try the suggested setup and see what you think.

Simply goto the Arc room settings in the Sonos App (Settings/System/Arc Room Name) and add the Amp as the TV surrounds - I will assume you already have the TV setup correctly for the Sonos Arc and Dolby surround audio.

The ceiling speakers will play the rear channel audio when outputting TV surround sound. 

For music playback, the default setting is the Amp speakers play ‘Ambient’ audio when playing to the Arc room, however this can be switched to ‘Full’ audio for music too. You will find that setting in ‘Settings/System/Arc Room Name/Surround Sound’

Hope those things help to provide you with the audio output you’re looking for in the room. 

I’ll go through the “Adding surrounds” from the ARC and choosing the “AMP as surround” option again.  It’s not a lip sync issue, it’s simply the AMP and the ARC not being in sync whether it’s music streaming or watching a movie…

Quick question, 

After adding the AMP as surround, can I still steam music to just those 2 ceiling speakers thru the amp?  I only want them to be surround when watching a movie.
Thanks

No, you cannot stream to only surrounds.

Looks like I need to connect the ARC directly to the TV and not the AMP.

Yes.  The Arc should be connected to the TV via HDMI-ARC, not the Amp.

Sorry to say that from the sound perspective, as well as from a Sonos sytem perspective, you seem to be going at this the wrong way.

1. In ceiling speakers are not really made for TV or home cinema use. They are meant to be used for (background) music. For TV viewing the sound from your speakers should appear to originate from your TV. With speakers built into the ceiling this is not achievable. The Amp (when used stand alone without a soundbar) is meant to drive two front speakers and compute a “phantom” center channel. You seem to have connected four in ceiling speakers, making the sound from the Amp coming from the wrong points.
2. The Arc should connect to the TV via HDMI and be put a couple of inches under the TV screen. If you want to you could then ad the Amp to power the surround rears - disconnect the front in ceilings. If so they are also probably also set too high but for surrounds this matters less.
3. You could also only use the Arc for TV viewing and use the Amp for music only, if you want to you could “group” the Amp with the Arc. Music will sound right, TV sounds will have a delay on the Amp.
4. The Sub can either be connected to the surround set up mentioned above (under 2), or you’d have to choose if you want to connect to the Amp or the Arc. It cannot be connected to two “rooms” in the Sonos app.

I can see you are limited in choices where to put your TV, but above a fireplace is not a good place to put a TV. It is too high up for viewing (which is your choice of course) but you could also run into problems caused by the heat - problems for the Arc or the TV.

Ok, sounds AMAZING… I just wish the 12” SVS Sub which is connected to the AMP directly would work.  Do I have to go with a Sonos sub now? :)  

Thanks for this detailed reply, will study it soon.   I may grab a few Sonos 1’s and use those for sourround and then dedicate the AMP to music only

I’ve got my Sonos ARc mounted upside down to access the buttons...how do I switch the R and L speakers?   

EDIT:  Doesn’t appear to be possible.  Flipping it now.

Upside down mounting also really messes up the Arc’s Atmos height sounds.