I'll echo what other's have said about getting an adult cat at least a year old rather than a kitten.
If you don't have your heart set on having a purebred, I think that adopting a shelter cat, or one in need of a new home would be a wonderful thing to do as well. Many rescues do in home fostering, and a foster family would be able to tell you about the cat's personality. Have you checked out Petfinder.com? There are plenty of cats on Craigslist that need homes too, and you can even sometimes find purebreds (not counting the BYBs that advertise there).
A lot will be changing in your life over the next decade or so, I'm sure, but that doesn't mean it is a bad idea to get a cat now. It all depends on your situation, your plans and commitments, and how your parents feel about caring for your cat when you're off at college. Having a cat can cause some conflict when it comes to finding housing, roommates, boyfriends, being away from home and such, and its understandable that people are concerned because it is important to be prepared for that. I think if you're a committed pet owner, though, and you are prepared for the extra responsibility, you will make it work regardless of your age. If you find a friendly, well adjusted cat, they will adapt as well.
I had a cat when I was a kid, and when I went to college, she stayed with my mom until I moved out of the dorms. We went through a lot of changes in the years she was with me... many different homes, different roommates and their pets, additional pets of my own, children, etc. With pets, finding places to live was a little bit harder, I paid a little bit more in rent or security deposits, a portion of my meager college income went to pet supplies, food and vet bills, but she was a special part of my life, and I wouldn't have had it any other way.