So after looking at various possible mounting points, I finally decided on using the frame sliders.
It was pretty easy to grind a flat spot then mount the brackets.
I also installed the Skene Designs Intelligent controller referenced earlier.
The cool thing about the controller is that you can have multiple brightness settings, one for the switch "off" position, one for the switch "on" position and one for high beams active.
There is also an alert feature that gets invoked when you flash your high beams twice.
Anyway, I'm really impressed with the build quality of the Mondo Motors lights. The whole package is really well thought out. I haven't ridden with them yet, hopefully I don't irritate other drivers, these things get BRIGHT (and a bit glarey to be honest).