I'd suggest a 31 Sonic or 32 Active Thunder. Both similar in size and architecture. Velocity and Fountain have relatively flat decks which will severely hamper your headroom in the cabin. The Sunsation does have a great cabin on the Dominator, and even better in the SS, but that is a newer boat. The Sonic and the AT will have a lot more room due to a raised deck. The boats you have mentioned are all great boats, but seeing you are down near in the salt, you will want FWC motors, so probably 496 Mag/HOs. There are plenty of 31 Sonics out there, but they are not going to be new enough in your price range to have 496s. Of all the boats you are looking into, the Velocity is going to have the most jarring ride in the rough, whereas the slightly bigger and heavier boats like a Sonic or Sunsation will give you a better ride.