Talk in conference rooms: considerations about microfone, loudspeaker and zoomable camera

Hi, I am interested in using talk as videoconferencing tool in our club.
We have video conferences, where around 40 people come together in one big room, join a conference and should talk one after another. They sit in a circle and in the middle are 3 microphones installed. At the wall are 2 loudspeakers installed in around 4 meter hight. Till now, there is a logitech lifesize system in the room, which should be replaced.

For me is not clear, howto prevent acoustic loops between microphone and loudspeakers.
In our old lifesice-setup i think the Set-Top-Box has it as a function in its preinstalled software.
But whats about the talk setup?

And how to use zoom and rotating for the cameras? Now we have the lifesize 10x and we found no api, to control them directly. It would be okay to replace them but they have a good resolution and it would be fine to keep them if possible.

We thought about installing debian or ubuntu on a client for the conference room, to plug microphones, cameras and beamer and use firefox for the webinterface of nextcloud talk.

Found out, that camera control is known as ptz “pan, tilt , and zoom”.

Axis cameras come with free available api, which should be quite easy to use.
https://www.mikekohn.net/stuff/ptz_control.php

Network cam to webcam conversion for selecting it in jitsi - should work in talk also.
https://4noobs.de/viewtopic.php?t=173

There are Panasonic PTZ cams with own control software and ip to usb software to use it in web based videoconference-software, but they are over 2.000€ each and the software is available for windows only. A linux or windows client does not matter that much, but i need at least 4 cameras and the old ones are still nice.

Any suggestions for different solutions?

I’ve had good results with the Logitech solutions for this, they have a modular system named Rally for your use case. This does all get pretty expensive though. I have run these things on intel NUC’s with Ubuntu which offers any video call software available to the users.