Looking for CPU + MoBo with ECC

Hi, I am trying to build home server for transcoding Plex + work as a NAS.
I plan to use FreeNAS + ZFS and RAID1 so I want it to have ECC.

I was hoping to get something affordable so I found:
Pentium G4560 - €55
MSI C236 Workstation - €125 (supports KabyLake since BIOS version D.6, so… not sure if out of the box).

or

Supermicro S11SSL - €180 (also not sure if it supports KL out of the box).

Any advice for better parts or should I go used?

As they say on the channel, always take a look at old enterprise stuff. A rack with a dual socket mobo, dozens of GBs of ram and a nice handful of cores will only run you a little bit more (if more at all) than a new setup, and that’s at potentially orders of magnitude more powerful than a system with new desktop parts that don’t break the bank. All I would suggest is a better thermal solution for PSUs, CPUs, RAID cards, etc to keep their life up and noise down

Now if that’s not an option… and it may not be unless you know someone or know where to look online, I suggest Ryzen - Get a ryzen 5 and find a mobo with ecc support

I would love to go with Ryzen but I am yet to find a single motherboard with 100% ECC support that doesn’t cost an arm and leg.

The problem with used parts is that on ebay most of them are from US or other foreign countries and the shipping cost will add up to a significant amount.
I intend to have the server in living room next to the TV so big rack will most likely be out of place so I was hoping for something in the micro ATX or mini ITX form factor.

Yeah, your options are definitely limited there. Ryzen is tricky because it’s up to the motherboard manufacturers, but you can still find stuff i’m sure
You might try the used/refirb market on amazon and newegg to keep shipping costs down.