bear in mind Jewel is only about 18, so insurance on anything larger than 600 is going to be diffucult and expensive...if you can stretch to a tl ins cost, go with a 748 - would imagine the buying cost would be similar to a tl for an early model and much more fun
alternatively, why not try an early zxr750 - great bikes and fairly large so should fit you, again bit cheaper ins than the bigger bikes.....just a thought.