Hi, Helge. I am 49, an American but my family came over from Trondheim two generations back. I'm a bit taller than yourself at 180 cm and 93 kg, and the 17' standard Guillemot fits me just fine. Don't be put off by the complexity of the project. Tools and skills needed are very modest, and none of the mistakes need be permanent. Any questions that you post here will receive prompt answers by builders who know from experience. Just do it.