Our sorority is Multicultural and we do allow people to join from 2 year institutions because we are an Up and Coming national organization. That might be your best bet, find one that is already established and allows members from 2 year schools. We all keep in touch via the internet. I am really impressed that your focus is service because a lot of people forget about the service aspect and just want to wear letters. Email me if you want some info. Or check out my chapter website
www.deltagammapiez.freeservers.com