And i just re-read your post after writing all this. but i'll leave this.
the assistant section might be worth reading.
I'm guessing one of the smaller alexas might be good for you, but i'll leave this here.
although sonos would let you choose either alexa or google (only one can be enabled on a speaker at a time)
https://www.sonos.com/en-us/symfonisk-by-sonos-and-ikea
the lamp is $179, and the "shelf" is $99
and will support airplay2
doesn't look like they will have any smart assistant support though
I have a HomePod, and several Sonos speakers (One, Play:1, and beam)
and have alexa and google enabled on a couple different speakers.
here's my take on the options.
(for a bit of clarification, the one and Play:1 have the same speakers and amps, they just added smarts to the one)
sound quality
they One/Play:1 is pretty much on par with the HomePod.
I don't have a stereo pair of home pods, but have seen people with issues in these forums, I do have a couple sets of paired of sonos, never had an issue.
Music Playback
Sonos wins this one no competition
If only for the ability to play from multiple streaming services right on the speaker. and being able to control from a single app.
With HomePod, you have to either...
---select the speaker from control center and then go to apple's music app to pick your music.
---use airplay to send to the speaker if you don't use apple music, once again speaker is selected from control center. And by using airplay, it means if you get a phone call, or browse to a website with auto play video, your music stops, and the website audio will come out the HomePod. Telephone audio will come out of the phone, but the music will stop.
both speakers support using voice assistant both for choosing music and which speakers to send too.
Siri can send music to an airplay sonos speaker, but sonos can't send to HomePod.
If you airplay to a sonos that supports it, you can forward that audio to all other sonos speakers
Assistants
Siri is definitely the weakest of the 3,
I use it for Homekit, and occasionally adding things to my shopping list.
Homekit is pretty awesome, and the only time it doesn't really work is if siri mis-hears me.
and haven't really tried much with the sonos stuff, but it was amazing how well siri could hear me, even if the HomePod was playing music, i was around the corner talking in a normal voice.
But still she gets it wrong a lot of the time,
haven't really played with alexa or google too much, but am stating to a bit more.
alexa and google both have home controls, but since i have homekit working once again, i haven't gone too deep.
for cooking, "how much does a cup of flour weigh", siri "???", alexa and google can tell me
for maps/store info, "when does the xyz store on this street open" siri "I can't find that info here", alexa and google can tell me
conversions "what's 32 deg F in C" all 3 get it
weather info, they're all 3 pretty much the same.