I plan on buying a 5s to replace the dying Galaxy S3 I have. I want to keep my Verizon unlimited data, so I'm going to fork over full price. What I'd like to know are answers to the following questions: Will the SIM from my GS3 fit in the 5s? Do the Verizon 5s phones come with SIMs pre-installed? Should I buy the full priced phone from an Apple Store or Verizon Store, or does it even matter? Thanks!