RE: Advice needed on sails sizes and new board
I would also support the Carve as a great board that will take you to the next level. It is relatively easy to learn to sail; but performs really well. Ultimately not as fast as an S-Type, but less technical and ideal for learning gybes etc. It's the BMW of windsurfing; fast, easy, comfortable.
I have two (111 and 133) and they both perform well in heavy coastal chop.