Choice one is something I wanted to do with my 6/4 Eastman case. For me, the problem was how to attach the backpack straps. Very interested to see what you come up with. I don't have the resources or skills that you or Bloke have!
I voted for the fiberglass hard case idea for no other reason than I want to see how you do it along with the pictures and write up that I suspect will be posted to accompany the project. Seems like a cool idea to me.