I have since bought more of this Biostar TB250-BTC board, and paired it with Intel G3930 CPU, and a M.2 64G SSD, DDR4-2400 4G RAM.
I have 10+ rigs of this setup running with 6x RX 470.....stable for weeks.   

It's my favourite setup thus far because of the M.2 slot for SSD, I don't even need to use any SATA data or power cables in the whole rig.