Installation Question(s)

I did a quick search, but found most answers are above my primitive understanding of a directtv installation.

So with that said, I looking for some answers regarding the requirements for wiring a town home for 4 total recievers, 1 being a hd-dvr.
But before going any farther then that, let me explain the current wiring configuration since it is a town home (not on the end).

Currently there are 2 coax cable lines entering the house from the back going to the main splitter located on the first floor, which is located in the closet (central location of the 1st floor). From there the line is split to all 4 rooms. With 1 currently being inactive.

Now, what I want to do is, in the living room I intend on putting the hd-dvr, which happens to be next to the back of the house, so I don't think running an extra cable will be that difficult. Where the remaining rooms will just have a standard tuner.

But I guess my real question lies on whether or not I'm gonna need both lines going into the house, or can I use 1 (of the lines going to the central splitter) for direct tv, and the other for roadrunner? Or do I even have enough lines running into the splitter? I don't want to do dsl due to the added cost of the standard phone line, which happens to be as much as I pay for voip.

Any help would be greatly appreciated. A call to the sales department led to some misinformation.