Penske 8987 Triple adjustable, and damn I wish I had more. Stock shock is a pile at anything more than comfortable street pace. If you contact Phil at Aftershocks Suspension, he has a lot of experience with ZX10s and aftermarket shocks.
I've had the pleasure of using both shocks but on diff bikes and have never been disappointed in either in terms of product quality/reliability. Depending on which model you purchase will determine what bells n whistles you get or not so the more knobs and screws there are for tweekin it the more $$$ ya pay.