Check out the Schubert Waltzes I believe there are 3 sets, I don't know all of them but the 36 Waltzes D.365 have some really nice ones.
I think they are all pretty much on youtube for you to listen too
[ Invalid YouTube link ]schubert+d.365
And the scores are available on IMSLP
https://imslp.org/wiki/36_Originalt%C3%A4nze,_D.365_(Schubert,_Franz)
They are all roughly around a minute each.
I think In terms of technical building I would point you to Bach, the well known notebooks of Fugues and Preludes have a solid foundation for making a competent piano player.
In terms of the other composers, accessibility to their repertoire for the level you are at, I think Schumann and Schubert, possibly some Beethoven. You will unfortunately find very little by Liszt, and I don't know anything about Wagner - in terms of piano compositions unfortunately.