Here's how to make the elevons and install the servos in the Synapse wing. Please see previous videos on the actual wing construction. Videos on fuselage and fit, finish, and setup are to follow.

Note the link to the original Armin Wing control surface video. There is a link in that video to an even more detailed version of the process.

The servos I used are EXI digital metal gear 9g size, but any servo in this size range with robust torque, decent speed, and good reliability should work fine. I do specifically recommend metal gear servos though.