The best way to gauge technical difficulty is to sight read the music.
As described in the comments, both pieces are easily available at IMSLP. Download them and play through them completely. By the end you will know which is the one you want to play. Specifically, look for:
- Sections you can't play. This includes sections you don't know how to finger, articulate, or interpret (musically). There should be a few but not too many. If there are too many, the piece is probably out of reach for your current skill level, and you would be better off with something easier for now until a few more skills are learned or improved. If there was nothing difficult or new, you might be better served with something that will push your skill.
- Boredom and interest. While this isn't technical, it is still important. Do you like the piece? When playing it, did you get excited about listening to yourself play something you've heard in the recording? Did you learn something new about the music? Did you like it just a little more than the last time you heard it? If your answers are yes, this is good. Otherwise, the piece will become annoying and boring, making practice unlikely and a successful performance impossible.
