Fox Watersports has been kitesurfing before it was cool. These guys have done their homework over the years, and they make sure to only stock brands and watersports equipment they stand by and would use themselves. Shop online or in person in their Buxton store. They also offer used gear for purchase.
If you're looking to rent equipment while on vacation in Hatteras, they offer SUPs, surfboards, windsurfing gear, and wetsuits.