Chad that is one sweet Ult.

On the topic of enlarging the ailerons. Unless you are going to 3D this thing it is not needed. That being said, I wished mine were a little bigger yesterday. I was doing some harriers into a hover and I could have used a bigger bite from the ailes. This is not what the plane was designed for so I don't falt it.

If you decide to go with bigger ailes. Using built up ones would be the way to go. If it was me I would extend the ribs to a point. Then before the rear sheeting goes on,cut the ailes out of the wing to the desired size. Then cap the LE of the aile and the TE of the wing with 1/4" stock and double bevel. Just be sure you put good hardwood mounting points for the horns to screw into. This would be a lot of work, but is also the right way to do it.

David