I should think there'd be something out there already that would fit the bill. Possibly one of the older designs. Is the BD-6 any good? Can it be scratch built? I suppose a Fly Baby would be too slow and drafty. Any speculation like this is probably fruitless, though, if we don't know the mission, what you're willing to build with, performance required etc. OTOH, if you're LOOKING for a design project, I'm sure you could figure out how to narrow a Tailwind or Buttercup.