NewEgg and Amazon have had them. They are out right now(except for overpriced resellers). The boards keep coming in and out of stock. I have been able to get 3 of them over the past 3 weeks. Keep checking and you will get some.
So far I have only created 12 gpu AMD rigs and they work great on Ethos hashing eth at 361mh around 1600 watts at the wall.
What processor are you currently running in your rigs if you don't mind me asking Smilee? I just grabbed one of these boards myself.
I run the cheapest I3's--- 6100 and 7100. I have only tried 12 cards so I dont know how it will work with 13-19 cards. Seems like it should work though. BBT on youtube has been trying to get 14+ cards working with no luck so far but i think he will figure it out eventually so I keep watching. for just reasons of size, complexity and length of usb cables....I am sticking with 12 for now.