Router vs. transmitter

Not too sure where to post this. I have my pc in my office however,we would like to be able to listen to the music from our pc on our stereo in the living room. I have spent the last couple days trying to find out which is the best way to go with this and have had no luck finding anyone with any solid info on this.
We bought a Leapfrog wireless A/V transmitter thinking this would do the trick however the transmitter has an rca jack which would mean I would have to unplug my speaker system on my pc in order to use this. Is there such a thing as a splitter so I can plug it all in at the same time?
We have heard various opinions on which is the best and most effective way to accomplish listening to the music on our pc.
Some have said to use a wireless router with a tuner card. Seems like a lot of equipment for what we need considering we have an ethernet connection and really dont need the wireless router for that.
Others have suggested a cheap pc to hook to the tele with a media center.
This is becoming very confusing and some solid solutions would be very much appreciated.
Really to find anyone in our area that has any computer savvy is difficult.
Thanks for your help,
D