It will be interesting to see how well you are able to stay under the 28 oz goal with plug in wing panels.
I usually build the fin and rudder out of sticks...but choose light 1/8" balsa sheet for the stab / elevator. I'll use 1/8" aluminum brazing rod bent into a U shape for the elevator half joiner, and just sew it to the stab to support it in the middle. Balsa saw dust soaked with thin CA works in inlay the joiner to the elevator halves.