Suggestions on Sonos speaker placement

I'd lean to the 300s as surrounds at the ends and slightly behind the couch. Use for TV and Atmos music.

The Fives on either side of the TV as a stereo pair for music listening. 

The Ones I'd put to either side of the window by the dining table as a Pair.

The 100s in the kitchen, above the cabinets. Try as stand-alone and as a Pair to see which you prefer. Maybe group with the Arc for TV use, depends on your sensitivity to the 75 ms delay that introduces to the 100s.

Group the lot for party use or as background music. Set the 300s to full mode for that use.

Thank you for the response Stanley_4.  I have actually already repurposed both pair of One SLs and Era 100s in different rooms that I wanted music in so I’m left with the Era 300s and the Fives for this area.  Would it make sense to put the Era 300s by the couch as you said and then put the Fives in the locations where I had originally shown the Era 300 in the kitchen and dining room as shown below?  The TV isn’t normally on while listening to music but I believe the app allows you to select what speakers to use while watching TV and listening to music.  If by chance the TV is on at the same time I’m listening to music, I could always select the Fives for music and the Era 300, arc ultra and the sub for TV use right?

I have a similar floorplan, and based on what I’ve done, I’d recommend the following: ArcU and Sub as proposed, 300s as surrounds, then use Sonosequencr ($3 app) to add the 5s as front speakers, placing a few feet out on either side of the ArcU, which dramatically widens the sound stage! I have a similar setup, also use the Soro app to create multiple EQ presets for TV, movies, sports and music. In music mode, surrounds are set to Full, vice Ambient, and despite all speakers being in the family room, it immerses the entire level. I also added a 2nd Sub, and in movie mode it sounds like a movie theatre. I turn surrounds off for sports as crowd noise can be distracting. And TV mode is essentially movie mode with surrounds and Sub/bass toned down a bit. With Soro, you can save as many profiles as you like, so sky’s the limit! And not sure about Android, but on iPhone you can also save them as shortcuts for easy setting. If you do decide to do this, do some Googling, there’s stuff you want to do, first. For instance, after setting up ArcU w/Sub and surrounds, run Trueplay, then remove all the pairings in the Sonos app, readding them in Sonosequencr (Trueplay won’t work once everything is paired via Sonosequencr). There’s an order in which things must be added in Sonosequencr, so pay attention to that. Then, in Soro automations, you can toggle on/off Trueplay based on which sounds better (settings from running Trueplay before are saved and can be applied then fine-tuned). This probably sounds like a lot, but it isn’t really, and once you get it set up it’s pretty hands-off, afterwards. If you’re not up for it, the ArcU w/Sub and 300s as surrounds will blow your socks off for sure. I’m telling you, though, adding those 5s as fronts will blow your mind!

Note to the OP:  Using 3rd party apps to configure your system, while it may work, it is not officially supported by Sonos, and may limit the amount of support you can recieve if something were to go wrong.  This is not to encourage nor discourage the use of those 3rd party apps, it is merely to inform users of the caveats to doing so. 

The 300s as surrounds are pretty impressive, decent on 5.1 but really shine on Atmos so I'd use them that way.

I have had single fives in a couple rooms and the sound was quite good, even a bit of stereo-image when sitting flat. The dining corner is nice as it will reinforce the low end, you might try different locations in the kitchen for that reason.

The Arc Room will stream music with pretty good stereo and very good Atmos sound. As folks have mentioned not perfect as the Arc isn't as wide as you would normally space conventional speakers. Personally I find it more than good enough for my listening. 10 years ago, when my ears were better I might have added Fives, or more likely an Amp and some overly large floor standing speakers. The spouse hated that setup!

Grouping the Arc and any/all other Sonos for music works perfectly, no sync issues in music mode. Be sure to try Full and Ambient modes for the 300s, maybe full for parties and ambient when sitting on the couch.

UnGrouped you could use the Arc for TV and the other Sonos for music.

Different folks have different reactions to the 75 ms delay on Sonos Grouped to an Arc for TV sound. The greater the (sonic) distance between them the less impact the delay has. I rarely do that here but Christmas dinner and football were happening at the same time so I tried the di ing room and TV room grouped so the boys could listen to the game. Nobody noticed the delay to the point it was mentioned.

You can use your setup as shown in the diagram with no problem and a great experience for movies and music.

Here are two alternatives :

1 Donot set the Fives as a stereo pair as the placement is not conducive. Set them as separate rooms when can be grouped if desired.

2 Set the Fives in the dining area about 8 feet apart as a stereo pair along the same wall. Consider a Move 2 for the kitchen. Much smaller footprint than the Five and its portable so it can be positioned for best listening position or used elsewhere when needed.