Still not sure which hardware is a good buy. Also I don't have much clue about setting up security properly.
But I will setup a node sooner or later.
Discussion
Well, if you have the hard disk space you could just start installing bitcoin core on your computer.
Just wait for blockchain syncing and boom - you run a full node 😉
For dedicated 24/7 hardware: buy any low power, used computer or laptop and repeat the process
OR
Buy a ready-made solution like umbrel, start9, raspiblitz etc.
Also thought about running a node on a VPS. Would be convient but probably expensive with ~500 GB disk space required. And obviously it has nothing to do with self-custody. 🤷