The frame idea was for the second wing above the first.

As for servos, that's up to you. If you have a spare servo you could use it as the wing will already be cut out for it and have the torque rods... You could then use a Y harness to connect the servos...

If you use a pushrod between the wings then You'll have to be careful when attaching the wings to the frame each time as the top wing could be out of trim. Or you could just have the ailerons on the bottom wings and just tape up the top wing....