One Zektor 16 source, 64 out audio matrix - the odds of needing more than 16 audio sources is unlikely
Add in 4, sixteen channel amp of choice
How many people are actually going to be living there? That should be a good measure of how many sources you might really need, then add one or two for just in case
I would definitely avoid sonos since your using rti (or any control system)
You could even do a little mix and match for multiple audio sources to give yourself greater functionality. Perhaps automonics, plus Bluesound or a fusion unit ( if your feeling lucky) or perhaps Lode Audio. I don’t know what drivers you have or don’t have available
Maybe even a cable box - does anyone do that still?