For kitesurfing in the Netherland you might want to go to Brouwersdam. Be aware that kitesurfing is very regulated in the Netherlands and you are only allowed to go kitesurfing in specific spots. Otherwise police will give you a fine.
Regards,
Tom
PS: you might want to check
www.kitehigh.nl. It is in dutch but in the tab you can see "spots". They will appear on a map.