WiiM is good but does not have Airplay. The systems that offer Airplay include Sonos, Bluesound, HeOS, and MusicCast. WiiM is significantly less costly to implement. So ask yourself how important is Airplay?
I would advise you to consider a multichannel power amplifier…there are many on the used or new market from Niles, Russound, OSD, often with 12 channels, that are configurable, bridgeable, with either class AB or D topology, and get as many WiiM Pro or Pro Plus as you require zones…and patch away.
The main argument for HeOS and MusicCast is if you want to integrate a TV/Surround system into the mix of zones. Those systems are built into AVRs from Denon/Marantz or Yamaha respectively, and both have solutions to expand into other zones within the platform. Bluesound does the same with NAD. Of these, I like HeOS best for ease of use, and Bluesound for ultimate best SQ, but MusicCast is by no means far behind.
Another path is to use Sonos Ports and a “Works With Sonos” AVR…like Sony, Onkyo, or Pioneer.
All of these require a well designed, stable WiFi network as a prerequisite.

