I used some 5' slotted angle irons and bolted through pre-existing holes in the cab.
I thought about the windshield frame, which would work with bolts rather than sheet metal screws. Add some washers between the frame and the angle iron so it will have clearance to not butt up against the button on the soft top. Mounting in the back just saved me time on cutting steel and drilling holes. Only problem I have, it shakes a little so the lights bounce. I don't like it, but until I find a solution, I'll have to live with it.
Depending on the curvature of the window frame (if any), you could heat up the steel with a torch and put it in a vise to give it a little bend and make sure when attached, it's not pressed against the soft top so it won't interfere should you remove it, though it will still make it difficult if mounts and attaches at the front like the deuce. At least the slotted angle iron allows you to virtual mount any light at any place with 5/16" bolts.
I'd also like to add, if you've never used the amber colored lights, I'd give them a try. Softer on the eyes while allowing you see through dust, fog, snow, and rain a lot better than white. That's why I ran both white and amber, white for the trail driving and amber for bad weather conditions.