Welch Allyn is the standard, although IMHO you don't really need any of the equipment. The best value you'll probably get will be to buy a used set off of a graduating student. There's a bunch of used sets on eBay every year, so just keep an eye open for one of these.
not sure how your school works, but I got away with not even buying one. the few times I needed my own (for PE tests or whatever) I just borrowed one from someone who wasn't testing at the exact same time as me... I'd ask around and see if any upper classmen say you could get away without buying it. Take this with a grain of salt because I'm just saying what my experience was at my particular school... it could be very different at your school.
I have a Welsch Allen set. If I had it to do over again I would have bought a pocket set. They are generally a little cheaper and much easier to transport. Like some have said you don't HAVE to buy one, but I hate the otoscopes/opthalmoscopes that are attached to the wall.