ORIGINAL: inverted flyer
2. Also, agreed, the saito 56 is light, but it's considerably longer than an equivalent 2 stroke, so I thought that for both esthetic as well as CG reasons, I might move it back some, to place it's mass where it ought to be... and so that it looks right
Yes, you can move the firewall back so the engine's mass ends up in the same place as it would with a two-stroke. In, fact you probably won't be able to get theCG back far enough unless you do move the firewall or resort to putting servos and/or the battery in the tail.
Personally, I'd keep the servos inside. It looks better, and the servos don't get coated in oil. If you feel the nylon pushrods are not good enough, you can use the yellow Sullivan rods, or get some carbon fibre pushrods from Central Hobbies. Run the CH rods through the standard nylon outer tubes.
Converting to pull-pull is also an option, but quite a bit more work than just using carbon rods.