Prop cavitation is caused by too small a blade area. There are several factors which drive how large a blade area is required for a specific
boat. These include horsepower, the
water speed at the prop (this is NOT the
boat speed), the
depth of the prop below the surface and prop efficiency.
I strongly suggest you buy a copy of Dave Gerr's "Propeller Handbook". It is written in an easy to understand way. It will be very unlikely that anybody on a forum can give you as accurate
advice as you can give yourself by
buying this book, going to the part about cavitation, measuring your own boat and calculating what you need. These calcs are simple, you don't need to be a technical guy to do them. And you will get an accurate answer.