finding the right org.

I'm wondering if anyone can help me out with a few questions I have...

First, I want to join a sorority, but I have a lot of questions because I am now going to be a senior (graduating in May) and am already 21. Is this really lame if I pledge this late?? I am also going to be going to grad school, though at a different university, so maybe I could continue my membership at this point?? My big concern is that I have waited too long to join and now it will be too late.

Second-- I have no idea how I would find the right sorority for me. (I know that if I rush, then I will have this question answered a lot better, but I also think that there is a big difference between sororities and all.)

Third-- Do most girls who pledge do it with a friend? My problem is that being a senior, none of my friends will want to pledge with me because they have already decided not to awhile ago and they'll also be graduating soon. Other friends of mine joined awhile ago and we don't talk much anymore becuase we've both become involved in different things.

Finally, is there a good way for me to find out more about the sororities? The ones at my campus are: alpha delta pi, alpha kappa alpha, alpha omicron pi, alpha sigma alpha, alpha pi, alpha pi gamma, delta gamma, delta zeta, delta phi epsilon, zeta phi beta, sigma alpha iota, sigma iota alpha, sigma kappa, sigma lambda gamma, sigma lambda sigma, and sigma sigma sigma. Are these all the same everywhere, or can they be called different names at other campuses?

I would totally appreciate any help that anyone can give for me! Thanks!