i hate to give into these but,Apple will never give you a lesser or greater version for whatever phone they're replacing I have an Iphone 4S Black 32gb it will always be replaced with one just like that.Except if its insurance like assurion
You will get the same model phone, color and storage.
They will not downgrade you and wont give you a newer model either.
They have plenty replacements in stock and if they dont they will order one for you.