Which should i get? IPhone 5s vs 5c?

So I'm buying an iPhone and I need help on a decision. I can buy the 5c quicker but I don't like the plastic back and it will be older quicker. If I choose to get the 5s, I can't buy it until next year somewhere near Christmas. I really like the 5s' looks can probably buy a 5c during summer. My sister liked to go into my phone and she learns the passcode by looking while i'm unlocking it and I want her to stay out. That's why I decided to get the 5s but I don't really want to wait that long for it. I don't have an apple device right now and I miss Having one a lot. What should I do?

p.s. The phones will be bought unlocked.
P.s. I will get a case for the phone anyways

Sure why not

5S BECAUSE HAS A BETTER PROCESSOR AND THE BIOMETRIC SENSOR, BUT NOTHING MORE… IF YOU WANT MORE FEATURES AND FUNCTIONS AND A MUCH BETTER PROCESSOR YOU CAN GET AN ANDROID DEVICE, THE SYSTEM GIVES YOU MORE OPEN POSIBILITIES, A SAMSUNG GALAXY NOTE 3 OR THE S4 OR THE SONY XPERIA Z1

In your case 5S, the key things you want are on 5S