Most classical vocal music published my major publishing houses, G. Shirmer, etc. They generally have their aria collections in both "high" and "low" volumes.
one of the best ways to do this is listen to recordings of other High Soprano's and see what Aria's they often perform and see what you like and dislike about the selected recordings. A good place to do this research is you local library as they often have a large selction of music.
