Replying to Ski size help (and i, too read the sticky thread)

so i already have my old race skis that i use for coaching and my PEs that use when i'm not coaching(i coach for my mtn's race team) but i really want to get a pair of fujatives too. these would be strictly for park skiing and occasionally messing around all over the mountain.
*i've never skied park before
*i'm 5'6" 120lbs

should i go with 159s or 169s?

initially i wanted the 169s, but i'm having a hard time finding a pair for sale(i want the 05s) so would the 159 be ok?