I don't know what all you would want to keep on your phone. I chose the 64 GB versions of the i4, i4S, and IPad3 and am glad I did because the 32 GB versions would have been too small to hold the stuff that I want to carry around. I am ordering a 64 GB i5 tomorrow. I would have bought 128 GB versions of each if they were produced. You can store up to 5 GB on iCloud for free. I personally only keep my iDevice's back ups on iCloud. I don't want to have to wait for music, pictures, or videos to download from storage to hear or view them. I have slow data connections when not in a wifi scenario, so I want my stuff on my device. My wifi, or my DSL I should say, isn't the fastest either.
Sent from my iPhone 4S or iPad 3rd gen, whichever I happened to have in my hands at the time, using iPF.net