You want to begin windsurfing and buy your gear right away? Thats all good but but you need to realize that often you quickly get bored of large volume boards (member 'Windsurferdagg' had this, he had a GO139 which he bought after he learned the basics but got bored of it after he got to a more advanced level). Seeing as you weigh 90 K, like me i doubt you'd get bored of a 140 L board any time soon, especially in light winds where you'll need large sails (but thats a matter for when you're actively sailing).
What you may want to do, is take the GO package but later, when you have sailed a bit with an instructor, or someone who'll teach you the basic stuff, ie, tacking, un-and downwind sailing and that stuff. When you get those techniques mastered and you have more then enough balance on the big board and you're thinking of smaller boards, then consder the GO package that you suggested but with a GO 144 (or if you're chosing from earlier ranges the 139), which is a board that will keep you afloat but will be a lot less stable in the beginning (when i went from a 200 L board to the GO 139 it took me 2 sessions before i mastered the board, but once i did it sailed great in >14 knots with a 7.6).
The package you suggest has great material, better then whatever I have and i've been investing in the sport for 3 years now. The only thing you may want to consider is waiting a bit with chosing the board right away and first going for a few practice sessions in various conditions and then switching to a smaller board then you forsaw... It's just a suggestion.
Haiko, AKA crazychemical