I started to learn kiteboarding here a few years ago and try to return as often as possible. Very helpful team trying to adjust everything to your individual needs, expectations and experience. Don't be afraid to ask!
The have excellent and brand new equipment (you can buy North Kiteboarding equipment at good prices too at their shop), experienced instructors from all over the world and a great location.
They also offer help with accomodation and can give you helpful tips for restaurants, markets and other nice places.
Best season to travel to Hua Hin seems Dec to April, where you find best weather and wind conditions for kitesurfing. My favorite time is February/March however.