I would NOT buy the $900 diagnostic kit through the school for 2 reasons:
1) you can get everything on amazon for ~$300
2) we had a TON of issues last year with the bookstore not getting scrubs and kits ordered through them in until literally months after classes started.
I would definitely buy an otoscope/opthalmascope kit, reflex hammer, tuning fork, obviously stethoscope, and blood pressure cuff. You are going to need to practice for your CEA's on the weekends, when the ILC is closed, so you'll want to have them to practice at home, and occasionally they'll be like volunteer opportunities where you'll need your BP cuff. any cheap brand is fine as long as it reasonably works, but I would definitely get the specific stethoscope they tell you to get!