My TV and receiver both crapped out and my guy wants to take this opportunity to upgrade the system by installing a new Sonos system for the home audio (sonos playbar, sub and Connect AMP) and wants to use the Savant PRO system to control the entire system.

Are there other systems I should consider or are these the state of the art right now?

I don't know anything about Savant other than it's supposed to be good but I've had several Sonos pieces and love Sonos. SO easy a caveman could operate it, my wife can use it too, and it plays your library along with more sources than you can shake a stick at.

I don't know much about Savant so not really sure what the benefits it offers are.
My father in law has the Playbar, sub, and 4 of the Play 5s as surround satellites mated to an 85" Sony 4K HDR, and Samsung 4K BluRay (that plays 4K discs not just upconverts).
There is no need for anything but the Sony TV remote and the Sonos App.
There is also no need to go to a movie theater.