Thanks a lot. Your comments are already putting things in perspective. Sounds that in the 7-15 knts range the best board would be the iSonic 150!
For my weight (~90kg), is the difference btw. iSonics 144L/85cm and 150l/93.5cm so large? Do the 8,5 cms in additional width and 6L volume help planning in the 5-10 knts?
What you also wrote about the sails makes sense. I would need a 11-12 m2 sail, yet even from 9.5 m2, I would need a new mast+boom!
Thanks so far!