Replying to Line chronic 13' vs volkl ledge 13' vs armada t-hall 13'

hey guys im looking for a ski that will last me my last 3 years of high school. im 15, 5' 9", and weigh 120 lbs. i ski 90% park when im in jersey but when i do head up north to okemo/stowe i like to rip some groomers and ski pow and trees. im an intermediate park rider who hits nothing bigger than a 55 footer and hits medium sized rails. im an advanced all mountain skiier who will ski pretty much any type of trees/backcountry. also, what size do yo think i should go with, based on my height and experience. 171 or 178? Thanks