Guilherme,
You have chosen a great manufacturer, however.....
Why fixed pitch ?
I have had discussions various with people about the benefits of a constant speed prop.
We have an MT 3 blade hydraulic CS prop on our 7.
It is a superb prop - a compromise, not the fastest, one of the lightest, not the most robust, by far the sexiest looking.
What it does do is give exceptional take off performance, very smooth cruising, good aerobatics and an ability to slow down like a sky anchor.
A fixed pitch prop gives a great cruise, a slow acceleration on take off and no real braking when closed throttle.
We take a long time and use a lot of money to build our wonderful aeroplanes.
Incorporating a CS prop of any manufacturer will enhance your RV beyond all recognition.
Mike