I'm also looking for a large sail, in my case to go on a Kona One. My largest sail right now is an Ezzy Freeride 7.5 and I'm 90 kg. I don't want to race and I'm just trying to decrease my planing threshold by buying a larger sail. I'm thinking about a 9.5 or 10.0. If the wind is too light for planing, I will cruise around with my old faithfull Dacron 6.0.
I researched the web and also understood that I should look for a 2 cam "free-slalom" sail. Since they are lighter than race sails, they can be easier to pump on a plane. They also have about the same low-end than the stronger race sails, but lack on the high end.
Rémi, your comment is different from widespread wisdom. Should I buy a race sail instead? Is the higher pricing the only drawback on your mind?