So that means you are going to use 2 separate channels in your radio gear. I don't know of a radio transmitter that has 2 separate throttle controls. You may need to modify a transmitter (the mechanical part, not the electronics). I would think about using a radio for a plane as they normally have more channels. Normally, the left stick is set for throttle and has detents in its movement. The right stick would be set for elevator control for the up and down direction of the stick. There are springs that will cause the stick to move back to center if you let go of the stick. If you remove those springs, the stick will stay where you put it, somewhat like a throttle control. It just won't have the detents.
I would still put both rudders on a single channel.
Your rudder control would be left and right on either of the sticks rather than a wheel control.