Hey bro
I used to ride a 10m Cab Element 'C' Kite, and changed to a 9m LF Session.
I was 52-55kgs when I was on my 10m, and now 57-59kgs on my 9m.
I can get out from 17 knots to a solid 25, and it would help if I had a smaller board than my 138 Cab Custom.
I would be going the 9m personally!
Good luck