How short are you?? It's been awhile since I looked at the Triple clamps on the zzr600 but I think it's possible to slip the forks up in the triple which can buy 1/2 an inch reach to the ground without hurting the handling too much. A custom seat can get an easy 1 inch. 2 or more inches from the seat isn't too hard but may be at the expense of comfort. And finally you can get a custom shock to lower the back.
How is your reach to the ground on the zzr600 stock? Can you get toes on both sides, balls of the feet?? How much lower do you need to feel comfortable??