Using the MSC 22-8 will give you a lot more usuable thrust at the same rpm you are at now. At both ends of the throttle. By reducing the throttle just a tad with a more efficient prop you will be able to maintain or increase the available power and run quieter.

The MSC props are also economical to purchase, are lighter than the Bambula and Menz, are more readily available, and with a little "shopping" you will find them on sale at Troy Built Models right now.