10 knots would not be enough for your 6.2 m2 rig on the Isonic 101.
Perhaps the iSonic 117 wide would be better, but you will need at least a
7.5-8.0 m2 rig to make that work at your weight in < 12 knots.
The iSonics are a bit "technical" to sail, and the Futura or Carve boards
might be better with your stated experience and the conditions.
The Isonic 101 may not be exactly 101 liters, but I would not think that
it's actually 96 liters.
5.8-6.2 m2 rigs are for 18 knots, not < 15 knots.
I would reassess your sail size range a bit if you truly have 10-15 mph (not knots).
As suggested above, for 10-15 mph at least a 7.5 m2 (at your weight) would seem