One question I have, Has anyone actually seen this guy in action, first hand? I'm not suggesting he is faking it. But you could do this with a couple of small cranes lifting you to make it look like you were flying.

If he is for real, I would try it with pneumatics. For example, the pneumatic motors in power wrenches are small, and some of them turn at extremely high RPMs. I would have two engines pumping air to a pneumatic motor on each prop. Perhaps there is added weight doing it this way, and this added weight would make the thing not feasible. But it is an idea.