Speaker Switching Box Suggestions

Hi folks. I'm trying to help a friend who wants to have four separate pairs of speakers working in four different rooms of his house. He wants to be able to select which speakers will play at any given time--from one pair in the main listening room to all four when he is having a party or whatever. He also would like to be able to adjust the volume of each pair independently. I'm trying to build a system in the main room that will turn him on to two channel audio so I need something that will not degrade the sound. Any suggestions? Which companies make something suitable (Niles, Adcom, ?) and which model would be best for me to use. Thanks for the help and if anyone has the right product they want to sell, please feel free to contact me to discuss.