Pretty much with whatever option you go with, you'll end up needing an electrician since it is a high school and the stuff still needs to be to code. Make sure the electrician specializes in theatrical installs: It could end up costing the school twice if he installs it wrong, or uses cheap equipment. And it would probably be good to have your crew watch over his shoulder during the work.
I second this comment. Whoever you get, make sure they are a specialist for this kind of use. As we found out at my school, someone who doesn't have specialized knowledge for theater/auditorium lighting is just going to get you into a whole mess of trouble. Someone who considers it a "hobby" or is a general electrician/lighting guy/gal is not the person you want to do this kind of work. Paying the extra money to someone who knows what they're doing is worth it in the long run.