Ok, got it.
I didn't understand your reply because the OP question was an SSH client that could sync SSH keys and password, not a way to connect to the machines.
I use backborg for backups.
I wouldn't use a storagebox (mounted on your VPS) because you would have data and backup in the same machine (problems with crypto and with human error like: ops, I've rm -rf everything 🙈😆) and with the same service provider.
I'd use Backblaze B2 or Wasabi.
When I've signed up was the cheaper.
I've just checked and it's $6.99/TB/month and Backblaze B2 is actually cheaper ($6/TB/month).
Are there other differences that you know of? There must be since everyone is using Baclblaze.
Did you receive it? How is it?