+1 Neuneck and Hiro...
editing how kafra storage works IMHO would take a serious bit of programming and could potentially lead some people off (those who are accustomed to the old method).
anyway if you notice it correctly, the current item-ID method is actually quite neat (similar to the Dewey-decimal System) because you'll find most cards in one block and items from the same "episode" or "area" will most likely be stacked together.
so yeah i know it's hard to browse through 600 items (my storage is continuously packed because i am always afraid that some misc items i thought should be NPCed would be used for a custom quest
), but you'll get used to it soon enough...
-w-