All the mods you said will work fine.
CDallas' admonition about the servos in the wing is valid, but my experience is that gravity is your friend keeping the water from intruding at the servo openings. I use wing-mounted servos and water CAN get in there, it just does not seem to. That being said, the LT-40 doesn't "need" dual servos: there's no flutter problem I have ever heard of with the LT-40, and it doesn't need flaperons. Your only advantage would be more headspace in the cabin area because the ail servo would not be hanging into the cabin from the wing.