With all due respect to those of you who have been doing RC models for much longer than I have, and who have probably shot more stills and vid from aloft than I have, I humbly submit that what I've seen on this thread does not impress me. For purposes of shooting stills or video, you are trying to re-invent the wheel.
I pondered doing a scratch-build for an aerial camera plane, but decided it was much easier to modify a humble GWS Slow Stick. And cheap, too. You can guess what I used for power and radio.
For the camera I chose a Sony Bloggie I got several years ago. It has a swivel lens head. Using Velcro and straps under the Slow Stick boom, I can mount it to point forward, backward, or to either side (no gimbal and servo arrangement).
I shoot 720p at 60 FPS. The aerial shot is a frame extracted from the last vid of the season. It ain't shabby, unlike the murky stuff shot with the keychain cams. I've had two, and both tapped out before I could even mount them on an airplane.
Not being a good pilot, most of my landings are more like sudden arrivals. In grass, fortunately. The Bloggie survives, and I await spring time for another shooting session.
BTW, my house is the one in the center of the pic, with the tan roof.