Your gonna be smiling so big the corners of your mouth will touch behind your ears, once you put that Cline on.

My ST3000 was ported and designed to develope peak HP at 7900RPM. Thats why I proppped it for about 7200RPM on the bench. I don't know where the peak HP is for the Moki 180. I always tried to prop for 7300--7500RPM. It will unload in the air to a little over 8000RPM and be right in the sweet spot. I imagine you could push it to 8500RPM on the bench, but your prop is going to have to be smaller in order to get those RPM. You'll make more thurst with a large diameter prop around 7500RPM than a little 17-10 twisting up close to 9000RPM.

Big thrust forumla:
Large diameter--low pitch
19-8, 20-6

Speed forumula:
Little diameter--higher pitch
18-10, 17-10

It's all about the same load factor, and the engine should turn the same RPM or very close with an 18-10, 19-8 or a 20-6 prop. But, you'll get 5 or 7 pounds more thrust from the 20-6 at 7400RPM than the 18-10 at 8800RPM. RPM is not everything. It's thrust that you want on an aerobatic plane. I wouldn't lug it under 7000RPM, but I also wouldn't prop it for 8000RPM either. Somewhere in the middle is where I'd prop it.