Kinda watched the first episode on an iTouch while at the library... heh
From what I remember, I do think that Giglianne will be a great model. Can totally see her as a CoverGirl or in any cosmetic ad. She has the perfect face for it.
Honestly don't think that Justin is that great of a singer. He didn't sound too bad with his guitar but when he was in the studio - oy. Gross.
It's hard to tell if Kara, Amanda or Ben will succeed with their dreams because there wasn't really a good preview of their acting BUT Ben totally fits the stereotypical 90210/The O.C male role. Ben could be a very successful GAP or Calvin Klein model (honestly). He has 'that' look.
But I do think that Amanda probably has the best shot at getting roles. She seemed to have the right attitude and is outgoing enough to really put herself out there where it felt that Kara is a little bit more reserved. Amanda could also be a swimsuit model

The whole idea of the show is awesome. Love it. Great for Big Brother withdrawls.