List of required components

• Hardware Raspberri PI + case
• USB WiFi dongle
• Micro USB cable + USB AC adapter
• Computer speakers 2.0 or 2.1 (Logitech example)
• Software open ELEC with XBMC (with UPnP enabled)
  Link for install instructions

If you don't want to use complex XBMC you can install small media renderer for your Wheezy linux distribution.

Way how to do that by Stephen C Phillips: blog.scphillips.com/2013/07/playing-music-on-a-raspberry-pi-using-upnp-and-dlna-revisited