I’m looking for a small FC that supports ardupilot. I’ve heard ardupilot has very stable flight, and I am looking to convert a racing drone into something for photography.
Right now I would say the omnibus F4 nano V6 is the best micro autopilot for ardupilot/arducopter.
You can read more about how to set it up here - http://ardupilot.org/copter/docs/common-omnibusnanov6.html
Or … Kakute F7 AIO