Matt, I also like your choice of the Scarlatti Sonatas. For a Sonata, I like Mozart K. 330, which I am also learning. If you want to consider Haydn---Look at the Sonatas , D, F, or e minor. Since I do not not you or your playing, I am taking your age into consideration. How about a selection of Chopin Preludes and a Nocturne. For Debussy--try--Gardens in the Rain, Prelude from Pour le Piano. You might want to look at the Poulenc Nocturns. You might want to look at the Dello-Joio 3rd Sonata--and do a couple movements. Best of luck. Brahms---Rhapsodies or Intermezzi.
Kitty