You could Install minimum a HC800 and run latest software 2.10.6, therefore giving you a C4-Sharebridge driver in each Zone on the system, giving you Airplay functionality for different Audio Zones up to 19 I think is the limit. Also with this software level you could add Spotify Connect driver in the same way to create Spotify Audio Zones if you just wanted to send direct from Smartphone or tablet running Spotify App.
Then you could add a Single Stereo Amplifier (C4 Speaker Point) to each Zone. The Audio Matrix function would then be done via the HC800 Director & streamed Audio would go over the network to each Zone.
That way you can have different Audio in different Zones and/or combine Zones to play the same source etc.