Upgrading to Larger Bike

I have a 2008 Kawasaki Ninja 250. I've owned this bike for a little over a year now and am ready for a larger bike. I am very short and petite (on my tippy toes on my ninja now.) Is there any certain Sports bike you'd recommend for someone my height? I'm looking for something in the 600cc area. I've heard that lowering a bike can really mess up the handling.. Is that true? Thanks!!