Go to the selfhosted community.
You may not actually be looking for a cloud setup (are you de-googleing, and want to host your own calendar and contacts sync?).
If you just want to ensure your photos sync to home, use Syncthing or Resilio.
But I'd still head over to selfhosted, and explain what you want to do - "I have these phones, these users, and this data, and I'd like to ensure that data is sync'd to a home device" - not how you want to do it (the cloud bit - it's not really clear what you need as a solution, just yet).
Also, do you have an off-site backup system for your home devices?
Those folks will have ideas.