If you are wanting a sport bike look into the Kawasaki Ninja 250. It is a great little bike! I am six two and 200lbs and I can ride mine comfortably. Plus you can find them cheap used and the motors in the bikes are hard to tear up according to my mechanic friend.
The bike has a nice kick but is also easy to ride for a beginner. I bought mine, a 99 with 8000 miles, for nine hundred bucks! It checked out perfect.
Enjoy!