As of right now, I have a Scientific Atlanta SA4200HD box with the cable card in it. If I get a Tivo HD, do I just insert that same cable card into the Tivo? Also, if I only have one cable card in the Tivo, I can still run the basic cable to the Tivo also, in order to get "dual Tuner" functionality, right? I know that in this case, I will only be able to record one digital channel or two basic cable channels at a atime, until I get that second cable card. Is this right? Would I need to involve the cable company at all in this case? Also, I know the capacity is 20 hours HD, but what is the max capacity for any recording mode? I think it's 180 but I'm not sure. One more thing: I've seen talk of people upgrading the Drive space using external SATA drives. What is the cheapest one of these available? Thanks!