Replying to Liberty LTE it is.

I've finally made the decision to go with the liberty LTE this year. I already have a pair of old Salomon 1080s for my teaching skis, 09 K2 Kung Fujas for those rare New England pow days or trips out west. I really wanna focus on my progression in the park this year and I think this is the ski to do it with. My only dilemma now is size. Im 6 foot 1 and weigh 155. Should i get the 171 or 178? My K2s are 179 and I feel like they're a little long for me. Opinions?