Suggestions for a fanless, low power home server?

My previous experiments with home server were done on a Raspberry Pi3b+. It had enough horsepower to run on different jails

– a syncthing instance;
– two repositories for my projects and the Zettelkasten (just basic jails with ssh. More than enough)
– the DNS

Unfortunately, the system seems unreliable on the mass storage side: two USB sticks (Philips) were too weak to run ZFS; I gave up ZFS and used two new ones (Samsung) seemed more stable, but I didn’t dare using them to store the whole jails. Then the Samsung microSD with the OS reached Valhalla and I take it as a «this isn’t a valid configuration for this task».

I was thinking using a thin client with two SATA SSDs connected through USB-C. I saw the HP thin desks and also something based on intel N100, but I cannot decide.

Does anyone have a suggestion for something fanless, low consumption and around 200€?

Thank you all!