It is already mentioned in another combination (Logitech Media Server and Picoreplayer) but Music Assistant and PiCorePlayer (SlimProto) is an option.
Benefit of MA over LMS is that it is also capable to integrate other player providers (like Sonos, Slimproto, Airplay, Snapcast, etc). However if you use a mix of player providers playing “in sync” might not be an option.
I would also recommend to start checking possibilities and sound quality first if you start from scratch and see what fits your bill. If you already have some old devices on hand in my case it were a Pi3, Logitech Radio and a Gear4 with Airplay try out MA.
Just recently I started with 2 devices with BluOS and appreciate HA integration over their own APP (need to use the APP to add new things of course or not? 
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