RE: Tabou 3s - really kick S?
Lots of these (3s) available second hand - which might mean people haven't liked them as much as the thought they would.
but why not commit to an actual freestyle board if that is what you want to do? The 3S is not a dedicated freestyle board, and will not get going as early as a freestyle board... there goes your light wind stuff. I would go for a JP Freestyle, a Starboard Flare or a Naish Playmate
in terms of volume - the fatc that you ask means you are concerned - 87 liters is too big a step down and would not give you much time on water. I would suggest aim between 95 - 105 ltrs
And whatever you do, keep the Excite