I am about to go through this process as well. Unfortunately I had a third party DVR attached to the current system. Guess what. They no longer support an external DVR. You MUST get it from DirecTV for $10 a month forever. Nice little revenue enhancing scheme, eh? They force the upgrade of their equipment and drop external DVR support so you have to pay them.
There is noting you can do about it if you want DVR capability. I chose to just not use DVR.

