al7478 re your comments in the where did you start....
Yes your cables should be the same length, maybe i was a bit anal but mine were done to the mm. It does matter.
you mention a sound card for when you are playing the music from the PC. Have a look at a sound bridge or a squeezebox or a Sonos.
I was getting fed up of the poor quality of sound of everything being played via the PC and got a soundbridge and this will play Internet radio and all the music on the PC's and the quality is so much better.
have a look.