Lightning payments are not stored onchain and have already been proved more private than monero payments
HN user
agalush
I just measured it by myself with a domestic power usage tool.
NetBSD because I love simplicity and because it draws less power than running Raspbian.
It is running Gitea, Prometheus and a bunch of small tools I wrote (weather monitoring, home automation, family data sharing and tools for my Kids)
I have a raspberry Pi 2 running NetBSD at home providing a lot of useful services.
It uses just 1.5W.
Any more recent alternative would consume much more power.
you just need to open one channel to another node (better if well connected) and all your payments will be routed through that node.
If you have multiple channels you have more routing alternatives and can choose the best one for every single payment.
If you're worried about the durability of your contents, you can publish them on multiple relays, even self-hosted ones.
Also, events are just JSON content: you can easily dump them on your local storage and republish on another relay whenever you want.
I don't know about the good GPU support and is not a rolling release, but Devuan is a systemd-free Debian derivative you might be interested with