Thank you for your answer. I think I come much close to my dreamboard

As I understand, for such light conditions (2-4 Bft) and mine 77kg the bigger boards would be quite OK, like C162 or GO155/170. Or even Phantom?
But if good days will come with 15-30 knots, will those big boards be still good to ride (of course with smaller rig like 6m2)?
In other words - what is the approx. upper limit for GO155/170, C162? Phantom?