Yeah thanks for the replies. Only think that is pushing me towards 5s is the built quality otherwise 5c perfect for my needs until I upgrade to iPhone 6s or 7. By the way does the iPhone 5c feels cheap or slippery due to glossy built or it feels premium. I am buying off contract therefore if I manage to save that 100 dollars I can plump up for a decent set of headphones.
The 5c should probably get two more major updates -- it's really the flagship of 18 months ago in a new casing, and Apple seems to give its phones three major updates (the iPhone 4 probably is on its last one with iOS 7, and it came out in 2010; the 3GS got updated till iOS 6, and it came out in 2009; the 4S should probably get one last update with iOS 8.).
So if we assume that Apple continues its past performance (not necessarily a safe assumption!) -- Fall 2014, iOS 8 and iPhone 6; Fall 2015, iOS 9 and iPhone 6s; Fall 2016, iOS 10 and iPhone 7.
It's unlikely that the 5c would get an update to iOS 10, but if past is prologue, then it should get iOS 8 and 9. So if you want two full years -- till spring/summer 2016 -- you should be safe with the 5c.
As for build quality and feel -- that's subjective. You should probably have a look at one in person. (I personally think it feels substantial enough, but I do use a 5s myself, and prefer having a metal phone.)