Yeah, 171 Reno Jib should be okay. You'll get used to it, and it's a pretty light ski too. You'll definitely grow into it, it saves a bit of money. If you buy 160 Reno's, you'll find pretty soon that they're too small for you.
I'm 14 and grew like 2 inches over the summer, you'll no doubt be growing pretty fast. I'm 5'7 now, I was like 5'5 during April haha