FreeNAS build help needed

Can someone recommend what I should be looking for in a MOBO and CPU for a FreeNAS build? 

ZFS, 6 bay, mini ITX

nasferatu?? with the avoton board?


Only place iv been able to find the ASRock C2550D4I here in the UK is Amazon, and there it is £254 ($430)!

Any suggestions for a more ubiquitous MOBO? 

i like Supermicro over ASRock for servers, and this is slightly cheaper--- but it depends on how many drives you want to run