Right now, if you're buying new from a store, only an 8GB will be available for the 5c. The 5s will come with at least 16GB.
I like the 5c myself but consider it does not have touch ID, 64bit processor, true tone flash on the camera, and a couple other features.
It's really up to you. What features matter most, what budget are you in, how much storage do you need, and what features appeal to you most?
Sent from my iPhone 6s using Tapatalk.