yeah... it depends upon how good of a skier you are, your height and your weight.
i weigh 115 and i'm 5'4'', just got 166 armada's, and i've been riding 160s.
the tips at both ends will take off some height in general, and if you want to mount your skis true center then you're probably wanna go for a longer ski.
but yeah, i'd say 169 fosho.