RE: Wind range for Isonic 145
The wind range, with your 7.5 m2 and 9.5 m2 would be 10 knots to a bit over 20 knots (maybe 22 if the water is really flat).
You aren't that heavy, and if you have good pumping skills you could be planing even a little earlier.
It depends on where you want to put your emphasis. If you want earlier planing, go with the Isonic 145.
If the low wind range isn't your first priority, then go with the smaller Isonic 125.
Hope this helps,