Several options to consider. . .
Check with your campus Counseling Center or Student Affairs/Development Office. They can usually make presentations or have a list of community contacts that can make presentations.
Check with your community mental health center or a private counseling/therapy office.
Check with a psychiatric hospital in/near your area. They often love to do community outreach stuff (and will have lots of info in current trends in your area).
(I work for a psychiatric hospital. If you let me know what town you are in, I can find out if we have a hospital in your area, and get you a contact number for them. PM me if you want).
Does your university (or a nearby one) have master's or PhD program in psychology? If so, they probably offer classes on substance abuse counseling. Some of those students would probably be MORE than happy to do a presentation (professors too), especially if that is their area of study.
AA groups will probably have someone that can come to your chapter and tell "their story", but it probably won't have clinical/education information (prevention, treatment, etc.) included. However, it will be a very personal story of one person's struggle with alcoholism, what they lost, what they learned, etc. It may be very beneficial to hear as well.
HOPE THIS HELPS!!!!! I think you have a great idea for your chapter.