I bought them from superbrightleds.com. They were $90 a copy.
LHBD-50K2-110W: Cool White
I have 8 of them right at 16', two which the doors cover when open. The white paint really helps with reflecting the light. They have 120° coverage with frosted covers. I did not install a dimmer, but have 4 each on a circuit switch. I'll still need task lighting on the benches.
I just missed out on a local sale that had great old industrial work benches with outlets and overhead lights. They looked like a Tektronix era desk. Still looking for several benches about the same height.