I'm pretty new to cat sailing and this board too...

I've had excellent luck with the 1982 Nacra 5.0 I bought used this spring ..... Yes, cats are different to sail than the monohulls I've been used to, but the Nacra has been very easy to learn - fun from the first time out, and no disasters despite my ineptitude.

As for capacity, I (140 lbs) have taken two 180 lb friends out and we've got plenty of room, and still go as fast as we want. The boat is very forgiving about where weight is placed. No instability or even noticeable slowdown as the heavier ones move slowly into their optimal place.