The elevator setup should be ok. It has the advantage that one of the servos does not need to be reversed. But it may be difficult to get identical throws.

I have the giant one so 2 servos are easier. You might go with a couple of Hitec 225BB servos. They are small enough to fit side-2-side. Or look at a low-profile aileron servo. I was dubious about using the 225's due to their size. But then I saw several pylon racers use them for everything on their "guided missles". I used them with a .91 on my Extra and they outlived the plane.

As the tail is tapered, the servos will not be inline with the horns. I added a 1/8" piece of ply to raise the back end of the servo up. Then the top of the servo is inline with the elevator horn. I also glued a small 1/8" piece of ply inside on the other end of the servo. so both sides have 1/4" ply to screw into.

If there is a lightening hole there, cut a piece of ply to fill the area of the "hole" and ca in place. Cut the servo opening then add a ply doubler behind to add strength to the seam.

All stingers are weak just behind F2. They will break at the front of the wing saddle. There is a small doubler that stops at F2. The plane will split between the doubler and f2. Some have made the doubler extend past F2.

I added 1/2" tri-stock epoxied to f2. Then covered the doubler-F2 joint with fiberglass/epoxy.

I had the .40 and have the Giant Stinger. Both are fun to fly.