If I were you I would find the most active/competitive racing group in your area and buy one of whatever they are racing. If it is catamarans, I would buy the most popular boat in the group. One design racing is really how you learn how to go fast. If a boat in your one design class passes you really learn something. If a boat with a different handicap/configuration passes you learn nothing. One design also creates many more situations were you get to use tactics.

Matt