After getting tired of RPis corrupting SD cards I just took my old Mac mini 2006, swapped the CPU for a Core 2 Duo (was Core Duo), flashed firmware from the 2007 model, installed an SSD (yea sure SATA 1 limits bandwidth but latency is sooo much better) and installed HardenedBSD. (For which I had to compile GRUB 2 for 32-bit EFI, because well the machine has a 32-bit EFI, and fuck no I'm not using CSM. GRUB 2 worked very well.)
Unfortunately there is an issue with the Ethernet: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=206567 so right now my home server is on Wi-Fi :D Which has been perfectly reliable so far, thanks to the good old Atheros card.