Adding Wireless Media Hub

I am currently using a wired home network system with Charter Pipeline
(broadband). The broadband modem connects to a Netgear RT-314 gateway
router downstairs. From there I have 3 CAT-5 wired Win XP Pro PC's
connected to share the Internet connection (the main server is about 10
feet from the router). Two other PC's are upstairs -- both within 30 feet
of the router.

I want to add a wireless media hub to pipe my music from the downstairs
server to the stereo system upstairs (also within 30 feet of the router but
one floor up). What would be the best way to do this? The media hub I am
looking at (Creative Soundblaster Wireless Music) has a 802.11b interface.
Other than Internet access, I mainly use Remote Desktop to access the other
PC's on the network. Also, I still have one open port on the RT-314.


Thanks,
Dave