To be honest, I used to have an ISP with dynamic addresses and it wasn’t a huge deal. The address only changed every month or two. I used afraid.org’s dynamic DNS service to get a dynamic address that followed the changes and created CNAME records for my real domain pointing at that. The actual connection was fucking awful but the dynamic IPs never caused any problems.

As for services: Nextcloud is well worth looking into for file sync and photo backup, especially if you’ve already got a file server running.