Iphone 8GB or 16GB…which one should I get..?

Hi! Im thinking of getting an iphone. I considered a blackberry but finally decided the iphone screen size would be more beneficial to me. Now my problem is choosing the 8GB or 16GB. I'm not sure if i would even us 8GB of space. The main reason, somewhat silly of why i want the 16GB is that it comes in white, but if i get a cover i would be satisfied with the 8GB since it is less expensive and i dont want to spend too much money. What is your opinion...or does someone know of a new phone coming out that is similar?