Death of the Family Reading Order?

So I just finished reading Batman: Court/Night/City of Owls, and I absolutely LOVED it, so I'm looking to buy the next Batman arc, Death of the Family. I am a little confused, though. What do I buy if I want the entire storyline and nothing else? Do I have to buy both the "The Joker: Death of the Family" and "Batman: Death of the Family" TPBs or just one of them? Basically, What do I buy to get the entire storyline?

Yes you would have to buy both. Batman DOTF has the core Batman series and The Joker DOTF has the tie-ins.