First my choice for next year is 133 111 86 and will cover from 10 to 5,6mē.
The new iSonic 111 change not only for what you mention, so you feel less heating the water and drive fast with and excellent control because the wet surface is less.
Yes the 9mē and 6,7 go well in this board. The fact is the lot of change we do accept really well the 9mē for speed in flat water and stable wind, when is more choppy and more instable wind I prefer to used this sail on the 133.
For the 6,7 same story excellent with the 111 in instable wind. I used it on the 86 when the wind is really stable and strong.
You are almost same weight as me so iSonic 133 with 9 and 10mē with 48 and 52 SL2 fins. You will never loose the planing in the new rules of PWA.
Hope this help
All the best