Which protocol (CIFS, SFTP or WebDav) to backup large amount of multi-user data?

I have a Linux server (Ubuntu 16.04) where I would like to mount an external "storage box" where to periodically backup several terabyte of server's data (both high and low-frequency changing), possibly keeping track of user's attributes (owner/group/permissions). The provider of these storage box offers the following protocols: FTP, FTPS, SFTP, SCP, Samba/CIFS, HTTPS, WebDAV Which backup tool should I consider? If you suggest rsync, as I would have first to mount the data locally, which protocol should I prefer for the mounting ? Would it be possible to backup user's attributes (i.e. mapping users between server and host ) ?