You want the smallest blade the engine will carry and not blow up. Fuchs props are great for this in my opinion (two blade). Menz and Mejzlik are both great to, narrow blades and fairly light.

For your 75, I would recommend a Fuchs 26x10.
My 100's (DA and 3W each) love a Fuchs 27x10 (nice and loud, especially the 106 QS, WOW!).
For 150's, a 32x10 would be awesome.

P-tip props look nice but they have a very wide blade, which bogs lesser engines down, my 106 rips a 27x10, but my older 100 wouldn't come close to a wrinkle. If I had a 26x10 PAC prop, it would be nice and loud on the 100. Essentially you would want to lose an inch of diameter from your regular prop for max sound.