A windsurf wetsuit is most often manufactured from neoprene, or a similar material. This material is well-suited for this activity, as it is both flexible and provides a degree of insulation from the cold water. They can vary considerably in price, depending on the specifics of the suit.
Stitching is important when it comes to a windsurf wetsuit. If you ride primarily in warm water (above 60 degrees) then a simple stitched design will work fine. However, for colder water it is highly recommended that one go with a wetsuit that has sealed seams.
A windsurf wetsuit is most easily purchased through a qualified windsurfing specialist. There are many of these retailers throughout the country, most often found near areas where the sport is a popular activity. Fortunately, if you do not live near one of these areas, there are many online dealers as well.