Ditto. I got the ASRock J3455M. If you can’t find this one (or the ITX version), look for the similar J3710M / ITX, J4005M / ITX, J4105M / ITX, J5005-ITX or J5040-ITX (some of them have ddr3, some ddr4, some have DIMMs, some have SO-DIMMs).
Alternatively, if you want something small and good looking, while not minding paying the premium, look for MintBox 2 or MintBox Mini 2 (with 2 Ethernet ports).