No, you would need two Amps - one Amp to power the two front speakers and one Amp to power the two surround speakers.

Read more here:
https://support.sonos.com/s/article/4717?language=en_US

No. A single Amp acts as one zone, meaning all speakers wired to it will play the same content at the same volume.

You would need two Amps. One to power the front speakers and a second Amp for the surround speakers.

If I then need two amps for the front and back channels, do I need to connect both to the projector? ( I would only have one ARC hdmi)

Or can I connect one amp to the other over wifi and connect the sub over wifi and only one amp to the projector via ARC

The Amp powering the two front speakers will connect to your projector’s HDMI ARC port. The Sub and second Amp will connect wirelessly to the first Amp.

got it and the ceiling speakers connected to the second amp which would be connected wirelessly will still be able to be used as the rear stereo channel?

I am also considering the invisible in-wall speaker by sonance, I assume these would be connectable to the amp as well and work just as good as the sonos ones?

Thanks for all your answers by the way you guys are super quick, really grateful !

The speakers connected to the second Amp will still be able to be used as rear surround speakers in a home theater setup. When streaming music, the two surround speakers can play as a full stereo pair (along with the front speakers) if you set the Music Playback setting in the Sonos app under the Surround Audio settings to FULL.

In-wall speakers powered by an Amp can work as surround speakers too. They would actually be a better option than in-ceiling speakers since it is usually recommended to place surround speakers at or near ear level rather than on the ceiling.

[Double-check the following with your dealer.  Sonance “Invisible Inwall” have limited distribution, so the dealer has plenty of margin and therefore should be more than willing and able to verify the specifications with you.]  The “Invisible Series” are 5 ohms nominal.  So “just as good as the sonos ones” except that you can’t use 2 pair off a single Amp.  But @GS already primed you for two Amps, 1 front 1 rear.  They are also intended for use with a 70/100volt commercial system, but they do have a “48 Watt 5 Ohm Bypass”, which means you’ll have to swap a jumper, presumably described in their installation sheets.  Also, the “optional enclosure” isn’t optional, IMHO, not unless you get the specs for back-box size and put the extra lumber into the front wall to make it yourself.  Just buy Sonance boxes, the speakers are already expensive-ish.  Good luck, and send pictures!

nvm