Did you use this motherboard yourself?
It looks like a good deal at US$60 including shipping, but I
found one that supports 12 GPU's for $90. However, it doesn't include a CPU, which will cost $30.
So I have to choose between $60 for 8 GPUs (30 day wait) or $120 for 12 GPUs (5 day wait).
I'm leaning toward the 8GPU MOBO because less cards probably means more stability.
It has to be one motherboard that can put at least 2 power supplies, yeah I know that you can do a diy here but for maximum safety, is better done internally.