Hi Orange Whip,
I had a season on a JP Magic Ride 104. (not the size you asked). They are brilliant in the medium and low wind range. It took me a few good rides to sort it out. i.e. where to put the straps and what sail in each 5 knot bracket
. What ever sail you normally use given a wind strength drop it 0.5 meter smaller to start off. Ie when I would have been on 7.5 I used 6.7 with 36 fin. It took off like no other. This pic is a 6.7 Fusion and Magic 104 in choppy Redcliffe.
For your weight I would suggest you look at 104 for 15-20knots. The other two you mentioned are going to be to big for 15-20. I'm actually getting a 118 to use in 10-15 knots and I'm a lot heavier than you.