I’d consider a pair of Fives or 300s placed on top of the kitchen cabinets and another pair of 100s along the wall past the table. If money isn’t an issue match the kitchen set.You won’t be wanting a lot of volume while eating and can balance out the kitchen and table pairs for room filling but not too loud sound.

If you group either pair or both with the Arc system for TV sound you will get a short delay, a bit of an echo sound due to the networking delays built into Sonos. For music there will be no delay.

You could do a second Sub later if your open space seems to require one, we have a similar space and find one Sub good enough for our needs.

Nice setup for the living room (i.e. Arc, sub and Era 300 x 2). The Era 300 will have to be mounted as recommended here depending upon distance from ceiling.

As far as placement of the sub that is a bit of a concern? Any sub will depend upon it location in a room to produce the best low-end without the listener pin-pointing where it’s located. Fortunately, Sonos has Trueplay which can compensate in most instances to allow the sub to sound its best in your room. However. location may be a deciding factor. Bottom-line is that where you envison the sub may not be the best location. You may have to experiment with several placements.

If I were looking for sound in the kitchen I’d consider four Sonos In-Ceiling speakers by Sonance shown in blue. They will require a Sonos Amp; but Tureplay can be used with them as well. You may also want to include a wall mounted volume control knob. It’s a lot more user friendly for ceiling speakers vs the app (IMO). Consulting a pro-installer is a good idea for in-ceiling and/or in-wall speakers that are not part of a Sonos home theater; especially so when the Sonos Amp is involved as well as a volume control.

You would also set the speakers to Mono to avoid stereo mis-cues when listening. Each person would hear the same sound no matter their position in the room. The Living room and Kitchen can be grouped together for music. Grouping for TV is not recommended due to a 75ms delay from the Arc. That would be true for any Sonos speaker not associated with the living room Arc home theater setup.

Note: You cannot Trueplay the Living room and Kitchen as a unit. Both rooms will use Trueplay individually to achieve the best sound based upon room characteristics . 

If you use four ceiling speakers for the dining room-kitchen area you should incorporate a wall mount Volume control for each pair because the kitchen area will be noisier than the dining area. Without the Volume controls, you’ll never be comfortable with the overall results. TruePlay will probably object to the controls. I’d gladly give up TruePlay for the controls. For a room the size of the dining room-kitchen area I’d use three pairs of ceiling speakers. Until you listen to the result, this will seem excessive. Also, alternate left-right pairing, rather than a row of left and a row of right. Again, this will seem strange until you hear the results.

If you are using only one SUB, I recommend central placement, rather than the far corner placement indicated. Sound is pokey slow and some listeners in the dining room might notice that the SUB seems “late”.

Even if you use wall, rather than ceiling speakers, I recommend six speakers. In any case use a pair for the sink area, not a single speaker as shown in your diagram.