Depends on your preference. I am 5'2" but prefer longer skis. I ride 178 Nurture's and 172 Lizzies in the park. But I don't spin and flip as much as I used to, so I can get away with longer skis.
Let's start with this: What do you want to use these skis for?
If you want to spin in the park, or want something that will be easier to throw around in the trees, get the shorter length. I don't think you will see too many negatives from buying the 169's.
If you want to ski aggressively at high speeds and don't mind sacrificing a bit of maneuverability, buy the longer skis. Worst case scenario is the 177's will ski long, and swing weight will be a bit much in the park. Depending on how you ski, they may cause issues for you.
Please post the dimensions/model of the skis you are looking at. Are they for park, all mountain, or powder? This could help us recommend a length of ski depending on what you want to use the ski for.