As it turns out, there are undermounts specifically designed for the AR Drone to carry a Go Pro camera.
The thing I'd prefer not to have is the GoPro's absurdly fisheye lens. Pthu.
But maybe there's some other lightweight options out there with lenses which aren't so wide-angled? Something that'll do at least a 4/3rds sensor at 23.98? If we have to shoot 60 then we'll just pretend all the footage is "overcranked" and we slow it down in post maybe? I really don't want to get wider than the equivalent of about a 28mm in APS-C.