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Should be Enough but May be Overkill

The 64 GB should be plenty, I have that much space on my 3rd Gen and I don't have any issues. A friend of mine has the 32 and is pretty happy with that one. I would imagine for your parents, depending on how tech savy they are, 32 GB should be enough. Even if they have a large iTunes library, I doubt they would need all of it with them all the time.
 
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