All of the Schubert sonatas are difficult to some degree, some more than others. His music is some of the most difficult to play on the piano because it it so transparent, similar to Mozart. It looks manageable to the eye, but it is very difficult to bring out a clear, concise melodic line.
That nonsense out of the way, the little A major sonata would work for you (I am not one to reduce individuals to pointless grade levels). The third movement sounds tricky, but it really fits under the fingers quite well.