[aephi alum]

Those sound like good choices for outfits. I especially like that second one.

I will warn you that many sororities wear black dresses at pref, and probably a lot of PNMs will be wearing black, so you may not stand out as much if you wear black. Alpha Phi at my school wears white, I'm not sure if that's an Alpha Phi thing or just that chapter's tradition.

For your hair, a simple but elegant thing to do is to take the top half of your hair and pull it back with a clip while letting the rest of your hair hang free. You get that I-have-long-hair look without risking having your hair fly around, fly in your face, get out of place, etc.