Which is better..?

[woahwoah]

I have officially decided on transferring to USC (Southern California), and I know that I'm going to need recs.
Where I live, greek life is not very prominent so I've only secured a few.

You've all said before to register with your local panhellenic alumnae (I think that's what it's called). I'm a little confused though. I found my most local one, but then I also found that each individual chapter has alumnae associations.

Would it be better to go through the one collective one or find the individual ones of each sorority I need? Is there even a difference?

Sorry if I didn't explain it right lol I hope you all understand!