When buying windsurfing gear you should devote most of your time for windurf sails and windsurf boards.
Depending on style you can currently buy freeride windsurf sail, freestyle windsurf sail, wave sail and slalom race windsurf sail. Before you start windsurfing you should decide what style will initially suit you... windsurfing sport is hard at begining but it doesn't have to be! Choose from North Sails, Gaastra, Vandal and Neil Pryde. Happy sailing :)