Also thank you for your input Energen.
While searching for a motherboard I mainly looked for the amount of SATA and M.2 connectors. Of course the IOMMU support (don't know how common it is) was also very important, so that the GPU could be used. For me personally also the NIC had be a Intel one, because I always had issues with other vendors in my gaming systems (latest being a MSI board with KILLER Network NIC, which "kills" my network connection with their drivers).
Considering that, I didn't really paid any attention to those other features. Which motherboard vendor do you usually prefer for Unraid?
Also I am really looking forward on building my first Unraid system. 😄
Regards,
SirAleks