Help me with buying the iPhone 4s?

I’m upgrading my phone, and I’m going to purchase the iPhone 4s, but I’m not sure which one I should get. I can’t decide between 16 or 32GB and 2 or 5 GB of data. I know I’ll use it a lot for photos and apps, as well as the internet, but I want to be smart about the cost.

Any suggestions on whether I should get the 16 or 32GB and 2 or 5 GB of data?