It doesn't really matter where you put the servos. Designers usually place them in the location that helps get the CG right, but being easy to install usually trumps even that. The method of getting the power back to the control surface is another can of worms though. You can do a simple pushrod, pull/pull, or rod in a tube. Of the 3, I like the rod in a tube setup. Sullivan makes their "golden rod" product that gives you everything you need to set it up, or you can buy a simple antenna tube and some 2-56 metal rods that are threaded on one end to slide inside it. With either setup, you get a very positive slop free linkage with the added benefit that your control rod can go around gentle curves. As i recall, you need a lot of cargo space inside your fuselage, so the rod in a tube setup will let you route your control rod right up against the fuselage side keeping the middle clear. Aileron control rods are so short almost everybody does a straight pushrod setup. That also works well if you put your servos in the back of the plane with the control horns on the outside.