There’s a nice Anthem MRX1120 available here for $1750 that’ll do everything you’re looking for.  Alternatively there’s an MRX720 that’s even cheaper at $1250 if you think it has sufficient power.  Both feature Anthem’s excellent ARC room correction. 
https://www.audiogon.com/listings/lisb1g21-anthem-mrx-1120-receivers

https://www.usaudiomart.com/details/649926459-anthem-mrx-720-receiver-4k-hdr-dolby-atmos-home-theater-receiver-72-channel/

I’d also return the R900s and get these Audio Engine A2+ powered, wireless speakers for the kitchen so you don’t have to run wires to the kitchen.  They’re also $270 cheaper than the R900s and will be perfect for getting good sound in a kitchen.  Get the B1 wireless Bluetooth adapter and you’re all set.  Alternatively you could get the B2 speaker if you don’t need two separate speakers and that’s only $199.  I have a B2 and it sounds great.
https://audioengine.com/shop/wirelessspeakers/a2-wireless-computer-speakers/

https://audioengine.com/shop/adapters/b1-bluetooth-music-receiver/

https://audioengine.com/shop/wirelessspeakers/b2-wireless-speaker-2/

Just some ideas to ponder, and best of luck. 

+1 @soix , but I would try a receiver (NAD, Denon, etc). My experience has been the room, setup and speakers determine the majority of the sound quality you will hear. Buy used and you can resell with little loss if you're not happy. I'm betting you will be. Keep us updated!

OK, you need a whole house audio solution. Get a Martin Logan Forte amp for the kitchen with ARC room correction and another one for the living room. It has a subwoofer out and the ARC room correction is amazing. The TV RCA outs will go to the RCA in on the amp. Download the Play-Fi app to your phone and you are streaming too:

https://www.martinlogan.com/en/product/forte

Review:

Conclusions: It is almost too good to be true!

How to use the playfi app to listen to tv or whatever in the kitchen/living room, etc:

I appreciate all of the great suggestions and advice so far.  I am attracted to the Anthem solution as it does appear to offer everything I'm looking for, and I remember lusting after their gear in college, so there's a nice bit of nostalgia there.  

The Forte amp appears to offer a lot for the price, especially with ARC included, but it's probably not complete enough for my main system.

General follow up question - does anyone feel as though I will be giving up too much in terms of pure sound quality by going with an AV receiver as opposed to a more stereo focused 2 channel integrated or separates?  Possibly in terms of soundstaging, black background and the like?

Thanks again.

You are going to be a lot happier with a two zone stereo receiver than just about anything else.  It's just simpler and you'll have independent volume controls.

Otherwise, something like an Anthem AVR with 7.2 channels because the 7 channel models let you dedicate 2 of them to another zone I believe.

You can partner the amp in the kitchen with the ML Preamp, the Unison in the LR. You will still get ARC, the streaming feaure, and can use it as an adjunct for straming whole house audio. Sale is $199-

Thank you both for the feedback.  Kota the ML solution appears super cost effective so I may deploy it for some other areas of the house.  Going to go with a more traditional setup for the living room and keep things a little simpler for the family.  Definitely a great deal on sale.

Erik I recognize your name from diyaudio.  Cheers mate.

In the end my sentimentality got the best of me and I ordered the Anthem mrx1120.  Has the power and features I need and gives me the ability to try Atmos at some point, so pretty excited to try it out.  Will report back once all of gear is received.

Cheers!

Good news, the Anthem has DTS Play-Fi! Get the Martin Logan Forte for the kitchen and you are all set!

MRX 1120 Features

• DTS Play-Fi® + "Works with Alexa" certification – Local and Streaming