Larger water sports retailers, such as
https://easy-surfshop.com/ generally have a selection of windsurfing gear. They may carry reputable brands and offer a variety of boards, sails, and accessories suitable for different levels of expertise. As for specific brands, I've had positive experiences with UNIFIBER and FMX Racing for their durable and high-performance windsurfing equipment. However, it's always beneficial to hear about others' experiences and preferences.