Contact Ken Reeves, email or call.
I'm going to want to know what boat you have, what motors you have, RPM and GPS speed at wide open (with the boat loaded as you plan to use it most of the time)
If its a custom one off boat, send me some pictures.
Any issues you are having with handling, ride, performance, etc...
What you want to fix or improve on.
I may ask you more questions too, obviously the more info I get, the better chance I have of fixing you on the first shot.
If you buy props from me and we need to change to something else, it's $40 each plus shipping to return the props.
If I have a prop we want to "test" I send it out for $40 each plus shipping and we can see what happens.