I have Dish Network and their top-of-the-line VIP 722 tri-tuner DVR. Two satellite tuners, one OTA HD tuner. It's an impressive piece of technology - it can record 3 HD streams at once while watching a recorded HD show on the main TV and a second recorded show on a second TV (SD) elsewhere in the house.
There is ONE RG6 that runs from the satellite dish on the roof to the back of the tuner for the satellite feed. That's for both sat tuners. There is a multiplexer/diplexer doodad right behind the DVR that splits the one incoming RG6 into two RG6's, each of which plugs into the back of the DVR. So there are two satellite inputs on the back of the box. But they are being 'driven' by one RG6 from the dish. I hope that makes sense.
For my OTA HD channels, I ran a second RG6 from my OTA antenna in the attic to the back of the 722. I have read that you can get a diplexer/multiplexer doohickey and combine both the satellite & OTA feeds into one RG6 cable. In my setup, it was a lot easier to just run the second RG6 than to mess with the satellite's RG6. Plus, I didn't want to mess with with the sat's RG6 anyway for fear of screwing something up. YMMV.
There is a THIRD RG6 cable coming *from* my VIP722 that goes to the RG6/cable distribution network in my home. The VIP722 (and a few other Dish receivers) provides an output signal that you can run to another TV for independent viewing (with UHF remote too).
So in my setup, it's two input RG6's and one output RG6. Setups can vary, however. I don't know about DirecTV, but in some parts of the country, Dish Network customers need two independent satellite dishes to get all of their programming. Many people around here have two dishes, but I have just the one that gets all three sats (110,119,129). With multiple dishes, I would not be surprised if you'd need two discrete RG6 runs. But I don't really know.
If you want to be sure, find out who your local Dish Network and DirectTV installers are. Give them a call and find out what sorts of cables & dishes are needed in your area. They'll know.
The Vip722 has an HDMI output that handles both video and audio. However, I use the optical for sound because my AVR lacks HDMI. I know, I need to upgrade. The audio works via HDMI because when the installer hooked up the 722, he just hooked up the HDMI to the TV and the TV had both sound & video.
And yes, you will want to have CAT6 run, not CAT5. CAT5 is only rated to transmit fast ethernet (100mb). You'll definitely want gigabit speed capability, so you want CAT6. CAT5 may work for gigabit over short distances, but CAT6 is a lot better. Especially when we're talking about home theater applications, where it's likely that sometime soon you'll be pumping HD video around your home network. There isn't much of a cost difference anymore either, so there's no reason NOT to go with CAT6.
Good luck!
