I've set up 3 Jitsi instances ( with one currently serving 100+ users; at least 15-20 simultaneously ). I also manage and maintain 5 other Nextcloud servers. Since you need only the video conferencing solution, I think the Nextcloud server would be overkill for your use-case. However, I can set Jitsi up for you.
I haven't set up BigBlueButton button before, I'd like to try and set that up for you, but if you're constrained on time, I can just set up Jitsi up for you quickly.