I use a Monoprice 6-zone Amp in my setup, and I wrote rules to control it in openHAB Here. It allows 6 different inputs including optical, and controls 6 different zones. It’s on sale now at $450, so much cheaper than the higher end options, and just as useful.
Either way you go, make sure you prewire the speaker wiring in every room you can think of having audio (hide the wires in the ceiling)…it’ll be much easier to add zones later on. Also, in my setup, the speaker/control pad wiring go to the same place (my rack in the basement). Some amps allow you to connect speakers to the touch pads, but for amps like this one with more juice, the amp outputs audio directly to the speakers.