Hi
Robotbird
I am 70-75kg and for my light wind kite last year rode the 14m SB2 awesome bottom end.
On Thursday on the river took out my new SB3 14m and it was great.
Also rode the 14m contra from last year that is a great light wind beast and me at 70kg would not go any bigger then 14m.Good thing about the 14m contra if the wind picks up to 15-18knts you can still comfortable in these wind unlike the SB3 14m if it pickup to 15knts its got a little too much power.
Hope this helps

Dan from Kiteaddiction.com.au