I think that after reading your advices I will avoid the Ruark device, I also remove from the list the Elac Z3 (which is purely mono).
The French device seem to be perfect to host the Pi, even if I will put the Pi above it (and not inside it, due to the high of the hat).
Now I am thinking between the French, the Sonos and the Bluesound (which isn’t clear if it’s or not a Roon ready device, or at least I understood that it should be “seen” from Roon).