I wouldn't personally put my static source inside the wing. The wing is surrounded by anything but ambient static pressure. It has hi pressure on the bottom side and low pressure on the top to provide lift; who knows which of those pressures will predominate on the inside.

I put mine in the Kitfox recommended location, on the left side, low and just forward of the lifting handle. Kitfox can give you dimensions. They also said the best would be an identical location on the right side, teed together with the left side tubing. I believe this information came with their optional static port kit.