Since I don't go to UofA, I'm afraid I can't speak on behalf of that school. I do know though, from my own experiences and from reading all of the rush threads that are here on GC, that there is NO set profile for what a sorority looks at. There are so many factors that are taken into consideration to join a sisterhood, like you mentioned, academics, personality, philanthropy, etc. At some schools, yes, there might be groups that could cut you for not being a freshman...but for the MAJORITY...sisters will look at YOU as a whole...and all of your activities will certainly help you out! Again, as for the portfolio, that is also a school by school situation.
Your best bet to answer your concerns would be to talk to someone in, or with a working knowledge of, the greek system at UofA. I'm sure you could find a Greek Advisor's contact info on their webpage if nothing else!
Best of luck!