Actually no PM necessary. Basically everything you wrote is pretty close to right on.
Things to keep in mind:
The motor itself cannot just be modified to raise up a certain height. The motor makes a full rotation from light off - light on - light off.
The "rod" and "arm" assembly that actually moves the headlight up and down will both need to be adjusted (cut down). If you only modify one part you will get your headlight to not go up all the way - but you will also have a headlight that won't go down all the way.
There is some pretty hefty cutting of the actual bucket necessary to fit the Hella lenses in there but they will fit once you get enough material out.
My bracket is shaped like this [ where the top and bottom are slightly longer to allow connection to the existing bucket. Holes are cut in the front for the lens and the mounting points - I will have complete adjustability of the headlights using a simple screwdriver.
Hopefully this winter/spring I will be able to get some time to work on the Supra - now that I have my daily driver (2006 Solara Drop Top).
It really is fairly straight forward once you get in there and get everything in front of you.
Keith