Well, if you think the etude will take the least time to get it done, then I am afraid that you are wrong, especially taking into consideration the Chopin etudes like the ones you mentioned. In general, college auditions take about 40 to 60 minutes. They ask you to propose the program. IF you are lucky, you will be asked to play only several works, but you might as well be asked to play the entire repertoire you have written down for the audition. I know one friend who applied for the Chopin Academy in Warsaw. Their entrance exam is soooo terribly difficult. Students had to really compete to prove who deserves to study there. I remember he played a very long program which took about 65 minutes! I remember he played:
1- Bach- Prelude & Fugue WTCI #22 (5 voices)
2- Beethoven- Appassionata
3- Chopin- Etude Op.25, No.1
4- Liszt- Transcendental Etude#4 (Mazeppa)
5- Chopin- Ballade #2
6- Ravel- Gaspard de la Nuit (Scarbo)
I might have gone way far from the subject, but he was asked to play the entire program he proposed for the auditions. Some other friends I know were asked to play the entire program with only one movement from the sonata they chose. But this does not mean you should prepare your program without caring about each & every note in it.
Going back to the Romantic piece, since you have about 10 minutes or more. Perhaps you should chose a REAL romantic work with great imagination and individuality. I would suggest something more musical than technical, because you will show them your technical abilities in the etudes. I believe Liszt would be a great idea, since you said Chopin is probably not your thing. In my opinion, Vallee D'Obermann would be a fantastic piece to add, but I must say its musically VERY difficult, yet technically not the very typical Liszt everyone thinks about. If not this piece, then Perhaps a set of Mazurkas would be REALLY interesting, as Op.24 of Chopin, a cycle of four mazurkas which takes about 13 minutes to perform in total.
As to the Etude, try Liszt Transcendental Etude #7 (Eroica). Trust me, it is not as difficult as it seems, but a great technical showoff work! If you are looking for easier etudes, perhaps Chopin's etude Op.10, No.9 or Op.25, No.1 and/OR No.2. The etudes YOU mentioned are more difficult than the ones I mentioned technically. If neither Liszt nor Chopin does the job for you, then MAYBE Ligeti could be the very good choice indeed. However, the rhythm will cause some MINOR difficulties in most of his etudes.
I might have written a long response, but I hope there could be some light in my ideas. and If you need anything else, the guys in here will be stunning with great ideas that will surely be of great value! GOOD LUCK! Greetings from Kuwait!