None of those are great options. You'll progress out of the Burton and K2 by the end of the year and despite what your apparent ass hat of a shop kid told you that Carbon Credit is too big.
Be looking for something 153-156. See if they've got a K2 Raygun, Flow Era, Flow Drifter, or Salomon Drift Rocker.
Go ahead, drink that kool-aid.
FS: Forum Sauce 142 $200 plus shipping
FS: Flux SE30 $75 plus shipping