trouble with audition pieces

[phototaker97]

so, i have been playing piano since i was five, and had a teacher for a time, but for the past six years (maybe longer?)  i have been self teaching and progressing at my own pace. i would not say i am extremely advanced, maybe and advanced intermediate player (does that make sense?).
i am a junior in high school and am going to apply and audition for oberlin college/ conservatory of music. the audition requirements are a composition by bach, a classical sonata (beethoven, haydn, or mozart), one etude of virtuosity, a piece from the romantic era, and a piece from the 20th or 21st century.
the pieces i have picked so far are: invention 14 in B-major by Bach, Sonata 16 no 14 by haydn (which i am having considerable difficulty with), Etude no. 2 in G minor by moszkowski, and Tarantella from "Songs without words" by Mendelssohn. i am still looking for my last audition piece.
now, as a kind of back up, i have also been looking at university of north texas's audition requirements. they are somewhat similar -1) Prelude and Fugue of Bach OR a complete Partita, Toccata or Suite of Bach, from which the faculty will select a few movements; 2) COMPLETE classical sonata (Haydn, Mozart, Beethoven) from which the faculty will select a movement; 3) Third piece in contrasting style (copy/paste from UNT website).

my question here is, should i overlap pieces such as the one by Bach and change from the invention to one that fits into a category specified by UNT, or learn a different one for that audition? i am already somewhat fretting about the five i have to learn for oberlin, but im not sure if its necessarily acceptable to overlap audition pieces. i am also considering changing my classical sonata to Alla Turca by mozart, as it seems more fit to my level and style.

the choir director at school offered to assist me in learning the pieces, and im sure i could ask her for help in picking the pieces i dont have yet as well, but i would at least like to have an idea about what i would like to play and to have studied the music a bit before i begin some in-depth learning.
i guess what i'm asking is: is it okay to overlap pieces? if so, what are a few Bach pieces that are an intermediate level that would fit the UNT specifications? what are the pros and cons of each of the sonatas, and which is better for an audition? can anyone suggest me some 20th or 21st century pieces? does any one have any other suggestions for me?

i know this is alot, but as of right now I'm kinda out there and alone, im not, persay, classically trained, and im not prepared to play mastermind, extremely advanced, genius level concert music.
^^^ there's probably alot of bad termage in there, but its how i feel right now, as im lost in a sea of high-level music that i dont feel ready play, trying to find something audition acceptable that is also on a level i am comfortable with.

the most recent pieces i have been working on before i started learning my audition music have included (but not limited to) pieces i have composed along with Fur Elise and music out of various level 4-6 lesson books i have acquired. 

[yohankwon]

1) everyone does a prelude and fugue for auditions
2) a Beethoven sonata is HIGHLY recommended for auditions. however if you choose a really difficult romantic piece then a Mozart or Haydn would be fine.
3) a chopin etude is also HIGHLY recommended for the etude
4) you need a bigger romantic piece (ex. chopin ballade or scherzo, liszt hungarian rhapsodies, etc.)
5) I would try to have the same program for all schools. My program for this year:
-(Bach) P+F No.11 F Major Bk 1
-(Beethoven) Sonata Op.2 No.3
-(Chopin) Sonata No.2 (I would not recommend this kind of work for college auditions fyi)
-(Chopin) Etude Op.10 No.5 "Black Keys"
-(Stravinsky) Danse Russe from "Petrushka" (same goes for the chopin sonata)

I'm going to apply to 8-11 schools this year. Just dabble around a bunch of pieces and see what you like. Your program should represent who you are.

6) Oberlin is not easy to get into, and same with UNT
7) I HIGHLY recommend finding a teacher ASAP, maybe your choir director
I'm done with this list lol hope this helps

[phototaker97]

thanks for the advice!!

So basically i have to be able to play stuff I'm not sure i can yet.

thanks anyway, it was helpful although slightly discouraging. im going to see if the choir director or maybe one of the band directors can help me, but im not entirely sure there's much hope given my current situation.

never give up, right?