On September 6, 2020 at 02:26, Brad Humphrey said...
The usual response is to use what you would sell to a customer. Makes sense.
Beyond that. You mentioned SONOS, so why not use either SONOS Amps or SONOS Port(s) into a multichannel amp.
For keypads, use either the Lutron Audio Pico (for SONOS) or the iPort xPRESS Audio Keypad.
I tried both of these keypads about a year ago. Did not like the button layout on the Pico and both seemed to have a bit of latency.