Here Amado from Bonaire.
I should say, when you want to buy a Isonic slalom-board and you are 10 years old, do not buy it to small. Ofcourse it is depending on your weight. I started on my Isonic 87 about 2 years ago when I was 10 years and 35 kg. I still use it with a 4.5/5.5 and 6.0 camber-sail depending on the wind. Because of the bigger volume you also can use it when the wind is not that strong. But, when you want to go slalom-racing with very strong winds it is better to use the isonic 76 with a big fin.
Overall , I think a isonic 76 or 87 (I do not kow how big you are and what weight you have) would be a good buy.
At our age we grow fast and you will have longer fun with
your board. You can send me a mail on
so we can talk about it in dutch or papiamentu. I hope I helped you a little to decide which board to choose, have a lot of fun with windsurfing and meet you some day here on Bonaire !!!