If you are using the board in swell/chop then the LF Proof 150 (151 x 43cm). Proof 160 maybe for you? Try both if you get the chance. I am 85ish kgs and the 150 gets me going nicely.
I have one and whilst there are better dedicated light wind boards, most of those are for flat water and go like a dog in the rough stuff. The Proof have a nice soft/rounded rail that is smooove in chop. I reckon the extra length helps tracking and drive better than a short/wide board.
Simple design, strong as fek and cheap as chips too. Goes tres nice in waves also.