Baroque:
Bach: Preludes and fugues ....there are 48 of them...all very good ! Take your pick!
Toccatas: In particular, the E minor BWV 914, C minor (912)and D minor (913).
Partitas: I love nos 2 and 3.
Italian Concerto in F (Would be a very good choice).
Mozart: K 330, K 283, K 533, K 570 are my favourites.
I can't really help you with Haydn as I'm not too familiar with it either.
For the Chopin etude: You should not be scared of 'fast' pieces if you want to play etudes ..and that too, the CHOPIN Etudes ! That is the point of learning them ...to solve your problems. In fact, I would recommend you to pick some aspect of your technique which is not good and you would like to improve and then pick the etude which addresses that aspect.
If speed is your problem: Op. 10 no. 4 is a good choice. Op. 10 no. 8 too (mostly for the right hand though.) Op. 10 no. 12 is one of the good etudes to begin with. I wouldn't advise you to go for the thirds or the sixths or the chromatic etude yet.
Your 2nd etude: There are lots of composers who composed etudes: Liszt, Scriabin, Rachmaninov are the most popular!
Liszt: Paganini etude no. 2, La Campanella, TE no. 4 (difficult one).
Rachmaninov: Op. 33 no. 6 (make sure of the numbering system ..I am pointing to the E flat major one!) is a good choice. I won't go for the op. 39 etudes yet.
Scriabin: Op. 2 no. 1, op. 8 #12
Also, Mozkowsky's etudes are very showy...well worth trying out !