@ 130 kilos, you are a BIG lad ...
as someone said - @ least 160 liters
at 100 kilos when I started shortboarding, I started with a 160/80 cm board - litres and width are your friends
assume you are also strong ...
i started with 7.x sails and with your weight I would suggest 8.x
maybe you can check Auzzie website:
windsurfinglearningcurve.com/