Thanks all. Some more progress.
I really wanted to mount the 100W LED's to a track mount so that I could easily fine tune their layout. Finally figured out to use window curtain track. Tracked down a local supplier and went picked up a couple of 12' sections of their heavy duty track.
This is the track used
Then I used a 5/16 bolt with washer to slide into the track and mount the light bracket to. This puts the lights 18" above the water which is the minimum distance recommended by Ecoxotic.
There will be 3 of these lights plus 2 rows of magenta stunner strippers and 4 of the Ecoxotic 6,500k Panorma modules. I think I will add one more curtain track a few inches closer to the front of the tank too, to give me another mounting option to play with.