Replying to Salomon Rocker2 100/108

I am thinking about getting the Rocker2 100's and am 1. trying to decide on the length (either 170 or 178) and 2. trying to choose a binding for them (Rossi FKS 120/140? Any other suggestions?). I am 16, 5'11" and weigh about 160. I want it to be a decent all mountain ski but I mostly ski off pitse and in the trees and moguls a little bit. In addition I may want it to venture into the sidecountry a little bit. Any help would be really appreciated.