My experience is somewhat limited with Audio AND Video distribution systems. I have only installed the Russound CAV and Xantech systems, both using composite video feeds to each TV
Russound now allows distribution of HD Video via their VM1 Video Matrix to the TV's . A number of other systems provide it also.
Here is some info on the Russound CAV6.6 which will only distribute Standard Definition via Composite Video on it's own
http://www.russound.com/rnet.htm
To distribute High Def video, here is info on the needed VM1
http://www.russound.com/video.htm
In a nutshell you will have the Systems Controllers located where the source equipment will be. The controllers have built in amps to provide Stereo Audio to each room "zone"
The controllers will also provide the switching to determine which video source is sent to each room. All controlled via keypads at each zone.
Wiring will require you run your speaker wiring from each pair of speakers to the controller. You will also run control wires from the keypads to the controllers "typically Cat-5e" Many suggest you route the speaker wiring so it loops down to the keypad location first, before going to the speakers in that zone. This will give you more flexibility to go with different systems in different price ranges when it comes time to trim out.
You also need to run the video feeds from the controllers to the display locations in each zone. Russound utilizes Cat-5e and video baluns / wall plate receivers to provide up to a 1080p image depending on your video source.
So basic wiring would be speaker wiring from controller to zone speakers,
Cat-5e from Controller to keypad at each zone
Cat-5e from Controller / Video Matrix location to the Display "TV" in each zone.
Wiring from your structured wiring panel to the Controller / Source equipment should include several Cat-5 and 1 RG-6 Quad Coax for each DTV receiver. I would run at least 2 additional Coax Cable for expansion shoud you decide to add a DTV Receiver, or if one might have a built in DVR. The Cat-5e will be for phone and data.
Other things you might wish to wire for.... If a zones keypad will be on a different wall than your display, you can have an IR Receiver located at the display which relays the IR Remote Commands to the keypad. This accommodates the habit of pointing the remote control towards the TV vs. learning to have to point it at the keypad to change volume, sources, channels...
For larger rooms and or where you might want more bass than to be expected from ceiling or in wall speakers, you might want to include a powered sub. In this case you might wish to route the speaker wiring to a discrete location for the powered sub, before going to the speakers.
Cost ??? You really need to investigate different systems, decide on which one sounds best for you and then get bids from qualified installers. To be honest, if your at your wits end now from just exploring different systems, you will be suicidal if you try to design, install and program such a system yourself.
Hopefully, others with experience in other systems can provide input as regarding wiring requirements and system features.

Russound now allows distribution of HD Video via their VM1 Video Matrix to the TV's . A number of other systems provide it also.
Here is some info on the Russound CAV6.6 which will only distribute Standard Definition via Composite Video on it's own
http://www.russound.com/rnet.htm
To distribute High Def video, here is info on the needed VM1
http://www.russound.com/video.htm
In a nutshell you will have the Systems Controllers located where the source equipment will be. The controllers have built in amps to provide Stereo Audio to each room "zone"
The controllers will also provide the switching to determine which video source is sent to each room. All controlled via keypads at each zone.
Wiring will require you run your speaker wiring from each pair of speakers to the controller. You will also run control wires from the keypads to the controllers "typically Cat-5e" Many suggest you route the speaker wiring so it loops down to the keypad location first, before going to the speakers in that zone. This will give you more flexibility to go with different systems in different price ranges when it comes time to trim out.
You also need to run the video feeds from the controllers to the display locations in each zone. Russound utilizes Cat-5e and video baluns / wall plate receivers to provide up to a 1080p image depending on your video source.
So basic wiring would be speaker wiring from controller to zone speakers,
Cat-5e from Controller to keypad at each zone
Cat-5e from Controller / Video Matrix location to the Display "TV" in each zone.
Wiring from your structured wiring panel to the Controller / Source equipment should include several Cat-5 and 1 RG-6 Quad Coax for each DTV receiver. I would run at least 2 additional Coax Cable for expansion shoud you decide to add a DTV Receiver, or if one might have a built in DVR. The Cat-5e will be for phone and data.
Other things you might wish to wire for.... If a zones keypad will be on a different wall than your display, you can have an IR Receiver located at the display which relays the IR Remote Commands to the keypad. This accommodates the habit of pointing the remote control towards the TV vs. learning to have to point it at the keypad to change volume, sources, channels...
For larger rooms and or where you might want more bass than to be expected from ceiling or in wall speakers, you might want to include a powered sub. In this case you might wish to route the speaker wiring to a discrete location for the powered sub, before going to the speakers.
Cost ??? You really need to investigate different systems, decide on which one sounds best for you and then get bids from qualified installers. To be honest, if your at your wits end now from just exploring different systems, you will be suicidal if you try to design, install and program such a system yourself.
Hopefully, others with experience in other systems can provide input as regarding wiring requirements and system features.