don't buy anything until you get to school! all the schools will have an equipment sale (usually run through SOMA - Student Osteopathic Medical Association) and you'll get a much better deal buying through SOMA rather then buying on your own (when they will really charge up the bills!)
you'll need an otoscope/opthalmascope, stethoscope, blood pressure cuff, tunning forks, reflex hammer (etc.) but again, wait to buy....some schools have very active alumni clubs that will buy you some of the cheaper stuff
any other questions, just ask me....