I'm building one myself at the moment, and also plan to put a Saito 91 in it. I intend to keep the rudder servo a the back, as although the 91 is lightweight compared to other 4strokes, it is still a few ozs heavier than the 46 size 2strokes the plane is designed for.

Therefore I still think the rudder servo out back may be needed. however I have moved it to the side as I think it is a bit exposed underneath.

As for prop, I will experiment, but I'm currently thinking of the APC 14x7.

Pull-pull systems are quite easy with a bit of planning. Fit the elevator servo first, as it is not too important where the rudder servo is placed, as long as the wires have free movement. As for exits, use flexible push rod inners as guides. These only need to be placed at the back end to guide the wires over/through the last former, and out at the back, through holes cut in the wood. Make sure there is a good few inches between the exit and the rudder. You can extend the guides al the way to the servo if you wish, makes it a bit easier to fee the wire through.

Mines coming along well, should be ready in a couple of weeks or so. Still waiting for the engine I ordered though. Think it is lost in the post.