For DIY consider a setup that supports ECC RAM to help prevent corruption. Any good server motherboard should do.

Unraid is pretty easy to get going on. That’s probably the direction I would take in your situation.

Also, if you’re not doing 3-2-1 backup now might be a good time to consider an off-site backup plan. That 4-bay Synology at a friend’s house with a VPN path would be an option for critical data. You could give them some partitioned space on there and on your new NAS to compensate for the power usage. Setup Borg or Restic and it’ll be encrypted on the remote NAS, and benefit from incremental and dedupe to minimize bandwidth usage.

Two of the things that I think are new vs the current system are:

Wallet: anonymous holding of currency without a custodian. You can’t hold fiat currency digitally today without a bank or other entity providing that service.

Transfer: moving fiat currency anonymously and under your own direction without intermediaries. You can’t make a digital payment or transfer in pure fiat currency today without that custodian providing the service (often through fee-based payment network). As a result, your identity is known when that transaction happens.

I don’t have a source to offer, but remember reading that the primary purpose for building, maintaining and expanding the canal network, all the way back to its origins in the 4th or 5th century BC was to deliver grain to the capital. So when the capital moved to Beijing, new sections were built for the same purpose.

So I would guess that these are general purpose cargo barges that could transport grain to the capital, and other commodities & goods (and political power) inland.

How about creating your own LAN within the untrusted network?

Something like an inexpensive OpenWRT router would do fine. Connect all your devices and the server to the router. They are now on a trusted network. Set up Wireguard on the OpenWRT router to connect to Proton so that your outbound traffic from all your devices is secured.