@Richarli I'm between 85-90kg, and not terribly experienced, but I found the choco 44 gets it planing pretty easily on either a 6.6 free race or 8.0, depending on conditions. I've used a 47 weed fin for using the 9.5 but I don't think I've had anywhere near as much planing time as on smaller sails.
The mast foot is about at center at the 130 mark on my board, and I may nudge it forward about 1cm at most from the pin being centered at that 130 mark. With outboard straps, it flies, but it was recommended to me to also move the straps a couple holes back from where I have them (furthest forward) for best performance, I just haven't done it yet.
@Lard let us know about the other smaller s10, as I'm curious, especially when it's 6.6 weather and I don't have my FSW board.