Ha! Love the binaural bison idea! It already looks like it's listening intently.
Careful going above the bison head. Looks like that may be right around where high-frequency vertical coverage from the PA speakers is likely to drop off.
As mentioned in the other recent thread about installed ceiling-hung mics, I feel a pair of spaced omnis, each placed in-line with the primary listening axis of the PA speaker on each side and hung something like 4'-10' out into room is the ideal setup for this type of installed arrangement. You get excellent clarity by being on-axis and directly in front of each PA, and that PA content will be clear, SBD-like and perceptually centered. You get as much or as little room ambiance as you want by adjusting how far out into the room the mics are from the PA (this is the main thing you may want to go back and tweak after the first few recordings). The wide split will provide a big, open portrayal of the room sound along with a wide, diffuse portrayal of the audience, rendering specific audience contributions less intrusive. And the mics will be close enough to the stage to capture some of the on-stage sound and live percussion transients.
You can run a typical near-spaced stereo pair most anywhere, but not this kind of setup. To my way of thinking that make it a good situation to take advantage of the opportunity.