I also build custom equipment, but as to the question at hand, I would make something that can overwinter a colony. Perhaps two frames wide, with glass at both sides. I wonder if bees are affected by the type of light used in photography darkrooms... this may be an option to avoid disruption to the bees, but insure viewability to passers-by... this may require a bit of research, but well worth the effort if it works!
justgojumpit