SkimI'm getting tigersnakes and I can do all boxes without thinking also some rails
Depending on how quick you are growing, go for the 164s. I'm 5"5 maybe 5"6 and I'm riding 168s and 170s for next season. I think you will be ok, you may have to adjust a little. It might be difficult at first, but you will get the hang of it.
sorry if it's not the case, but you look like someone who will continue to grow up for still a few years. Your skis can last for a few season so you should go with the 164. 171 could have been good for you but since you're not a super advanced skier, you will have more ease with the 164.