Law School- Letter of Recommendation?

[oooolala]

I'll be applying to law schools and I have chosen 2 out of my 3 referees from academic field. I would like my 3rd one to be from a non-academic field. I am in a dilemma right now with my 3rd referee. I don't know who to pick. I volunteer for Amnesty as an office assistant, I do a lot of administrative work and my Supervisor knows that I am an extremely reliable worker. I have been there for 8months. Supervisor only knows me as a good worker, doesn't know me personally that well though. However, since its a position at Amnesty, I don't know if that will make my referee look more appealing. The other extra-curricular activity that I am involved in has been for 3 years. It is a cultural club for my university. I have been working with the vicepresident and president very closely. They know me well as a co-worker, a dedicated member and as a friend. I have promoted, raised money for this club. I have even helped out in raising money for underprivileged kids in developing countries. But at the end of the day it is just a university club whereas Amnesty is AMNESTY. So who do you think I should ask to be my 3rd referee and why?