RE: early planing slalom board
hypersonic 111 or isonic 133. from what I understand, the s types require more power to get planing. They like to have more power.
I know I can get planing with my hypersonic 111 in 13 knots. Maybe more if I tune my sail and get used to my board a bit more. I use a 7.6 naish redline and am 66 kg
just put in my 2 cents...