If your using Hitec digital servos, Find someone in your club that has a servo programmer, and reverse one elivater and one aliron servo. That way you can use a non reversing Y harness. Your 6 channel radio realy limits the setup options on a bird with this many servos.

The choke is easy to rig up. with a pull rod from the bottom or front of the cowl.

On the Zenoah in stock form no battery is needed. If you have it converted to electonic ignition, the huge coil and flywheel is removed saving a bunch of weight on the nose, and a battery is used to power the ignition mounted in the rear case of the engine.