as for the board, look for a rather large twintip. There's all the time discussions about whether a directional is better or a twintip, but everyone seems to agree that a twintip is easier. You won't loose so much time learning to gybe, so you will have lots more time in the straps and thus on the water. You can then later one get yourself a mutant or other directional, if you have tried one and think the better sailing characteristics justify the hassle to learn the gybe. I just swapped my beginner directional for a twintip and tried it first time this weekend. It was a blast!
Anything from 170 cm upwards should be good.
If you have no windsurfing or wakeboarding experience, see if you can arrange anyone with a boat on these no-wind days. If you practice behind a boat (a lot easier then when you have to steer your kite at the same time), your learning curve will be way steeper. The idea is that you first learn to control the kite and the board seperately and only then go for the combination, as soon as these things come more naturally.
Nogmaals, veel geluk ermee! (Sorry, not a Dutch person, but a Belgian (Flemish)