RE: S-type 137 vs Carve 133 ????
define light wind, I think otherwise you could be quite disapointmented.
C133/ST137 not light wind boards as in < 15 kts! Not if you want to go "VROOM". Then you sould really consider an FT138 (with a 9.5) or similar. ST137 gybes and rides more like an FT138 than a C133 anyway.
I can understand why you're confused, know the feeling.
If you have the possiblity then test the board in the intended conditions before buying (I'm stupid, I always test if after purchase, not a good idea).