Hey Fernando - there is not really such a thing as the "best" aerobatic prop. Everything is a compromise. No prop reasonably suited to your Pitts is going to be vastly different from another. We are talking relatively small differences. It depends on your goals and how you fly the airplane. From a pure efficiency standpoint, a metal 2-blade Sensenich cannot be beat. Lighter wood/composite props have advantages, but not in terms of pure performance. Lighter props reduce crank/flange stress. Unless you have a hollow crank and/or light crank flange and are doing lots of snaps and gyro style maneuvers that rapidly rotate the prop disc, you are better off with a metal prop. What type of prop do you currently have?