Hi. You would need a Sonos Amp to drive the ceiling speakers (which are not made by Sonos).  Yu might be better off forgetting the ceiling speakers and getting a pair of Ones or One SLs.  Just something to think about.

Hi @giossen 

As said you would also need a Sonos Amp. However Sonos does have branded architectural in-ceiling speakers which can be found on the Sonos website. The speakers are built to Sonos specs by a company called Sonance. On the Sonos websites they are listed as Sonos Architectural in-ceiling speakers by Sonance. Those speakers are also compatible with Trueplay to allow you to tune all components to your room. TruePlay does require an iOS device. 
 

Note: In-ceiling speakers used as surrounds can limit placement of your furniture. They need to be directly over or just slightly behind the seating area spaced left to right.

A Sonos One (for voice assistant) and a Sonos One SL make more sense for placement options. Using the One SL reduces the cost slightly. Of course you can use two One’s if your pockets are deep enough .