Imagine the GSX-R 750, but at 1/2 the price, 1/3 the power, 2/3 the weight, and with better handling. That'd kind of get you in the ballpark of a DR-Z400SM. It's a "hooligan bike" that you can also ride in the dirt, with a few mods. If you're shorter than 5'6" you'd probably want to shave the seat and possibly lower the suspension a little. It's a bit easier than a GSX-R 750 for a small rider to handle safely.

Some of the 250cc supermotos are even easier to handle, while being able to rip through the twisties.