Re: How to determine minimum recomended ipad storage
Just use common sense. If the music and movies will be streamed instead of downloaded and stored on the device then 16 GBs should be more than sufficient, depending on the size of the "few games" you referenced.
Re: How to determine minimum recomended ipad storage
Photos can go in cloud based apps like Box and Dropbox. Just manage your space to best meet your needs. Mostly you can't put a lot of music on it with only 16 gb.
As much as your budget allows. You can't add more later, and you don't want to always have to rely on Wifi and a data plan to access your stuff, so get as much as you can up front.