Iphone or Ipod touch..........................................?

Hi I was wondering if I should get the iphone 4s or ipod touch 5g? I am 14 years old and my parents refuse to get me a smartphone, so I thought that I couls get a unlocked used iphone 4s and put my own sim card in it. I also am considering the ipod touch 5g because of the bigger screen and more memory than the used iphone, but I can't decide. Both are the same price except the iphone is used and the ipod is not. I need opinions on what to get. Thanks for all posts:)