You need a soundcard that supports surround sound- Example audigy 2. Most speakers are wired- I will edit this post with links to a logitech system one similar to mine, but with wires that can be unplugged- standard speaker wire- so they can be any length. Logitech also has a wireless system for the rear speakers. Hold on.
These are one up from my speackers, which I love. They have spring clips for the speaker wire- so all standard speaker wire will work with them. So you could run the wires where they wouldnt be noticed. This also requires only one plug unlike the wireless ones- which I am looking for.
Here is the logitech wireless set- I would personally say go with the 5500s and their wires- less possible issues, and since you can lengthen the wires as much as needed, you wont be tripping over them. But these are the wireless for ya to look at.