You're outta luck if you're looking for a wireless system that won't degrade the audio quality. Right now, wireless systems won't even let you connect to a regular speaker. The only ones that I've seen are self-powered and you're wedded to whatever speakers hook up to the receiving unit.

In the future I can see distributed wireless systems as more speakers build the DACs and DSP circuitry directly into the speakers. Right now, there's a growing selection of high end speakers that have the digital decoding and amplification built in, but the wireless signal distribution is not part of it yet because you need a lot of bandwidth to do high res uncompressed digital audio. You still need a digital cable of some kind.

Right now, the market for wireless audio the way that you describe has yet to materialize. Your best solution is probably to go with some of the flat speaker cables that are available and run them along the floorboards or under a rug. There are a lot of ribbon speaker cables out there, you might want to look into those and other flat cables.

http://www.ramelectronics.net/html/flatwire-FLT.html