Agrelon, thanks for your reply and recommendations given previous threads.
It does make sense as you say to go for the 11 m2 Rig (which is going to be quite expensive) on an iS150. Many people like that board in the forum so it would probably be beat choice.
My question though is whether an 11 m2 on an iSonic 144 would be as good for early planning as the iSonic 150 in my weight-class (~90kgs).
While the iS144 is only 85 cm wide to iS150's 93 cm, you can buy the iS144 in WoodCarbon (iS150 only in Wood), which is ~1,5 kg lighter!
Thus the question to the team (Remi, Roger, etc) is iS144 WC vrs. iS150 W on an 11m2 - which one will plane first in flatwater conditions in 7-9 knots?