I recently struggled with this scenario and here is how got over the challenges described above including the audio EDID problem. I did not want to have multiple BD players and did not find any cheap, small AVR that could decode multichannel audio. Everything now works great.
MATRIXOctava 4x4 HDMI Matrix
I went with this because
1. The 8x8's are quite a bit more expensive and I can daisy chain these when/if I need more inputs/outputs
2. It allows you to set the EDID parameters
EXTENDERSAltona AT-HD4-V40SRS HDMI Extender
$329.99 x 3
1. Sends highest quality signal (1080p@60Hz/36bit/3D/7.1audio) over a single Cat5/6/7
2. Has bidirectional IR which is very helpful in coordinating IR signals into rackIogear GW3DHDKIT Wireless 3D kit
$279.99 x 1
1. I use this to one zone where I don't have Cat5
2. Works well upto about 50ft through a few walls
3. Has unidirectional IR
In the Home Theater I use a Denon 1712 AVR which handles all 7.1 audio signals well.
As explained above in order to get full 7.1 audio in one zone you have to set the EDID on the matrix to 7.1 audio in all zones. I have two legacy plasmas in two zones which do not have separate digital audio inputs. When I plugged the HDMI cable from the Altona receiver to the TV I got digital noise. After a lot of experimenting I found the following solution.HDMI Audio Extractor
Input - HDMI cable from the Altona receiver
Outputs - HDMI pass through to TV, Optical Audio to...GefenTV Digital Audio Decoder
Output - RCA stereo cable to analog inputs on TV
These two devices are much smaller and cheaper than any AVR. They are mounted, along with the Altona on the wall behind the TV. Again has worked perfectly for the past month or so.
Hope that helps...