So you will have 4 motors placed around you and will be controlling this from the seat in the middle.
This means you control lift by increasing the speed of the motors and flight/direction by increasing 2 motors by more than the other two causing the platform to tilt and directing the thrust in the opposite direction to the one you want to go in.
I Think.
So you have your main speed/lift control and then you will have to vary the thrust/speed of the 4 motors via the stick to obtain direction.
Eg. The stick controls 2 dimensions, forward, reverse, left and right and another control will handle the altitude.
This is how the model quads work as i understand.
So some sort of joystick control for biasing of the motors and 4 motor speed controls.
Saw a joystick once that moved in 4 directions and you twisted the stick to control speed, maybe set it up so if the stick is released the unit goes into hover.
Daz