You only need the 8gb iPod touch. Plus, if you were to do that, you would not want to up-charge to $900 for it, at least not look like you are.
Say you charge $500 for the files now, on your next pricing change, start charging $800 and include a *free iPod!! The goal isn't to make money on the ipod itself, the goal is to impress the client without hurting your bottom dollar. Also, the ipod shouldn't affect your album sale at all. It's not replacing the album, it's replacing the DVD of images......which is only available to purchase if you buy an album

BTW, your photos will be shown to many more people if you go with the iPod.
But that said, you still need to have nice packaging either way.