On the client side, I use rioplay (http://rioplay.sourceforge.net) and take advantge of it's ability to play shoutcast streams. It has worked flawlessly for me. I even got it to work with my HPNA network with the help of the developer.

On the server side I use the orginal Rio software and I have set up my PC as a shoutcast server using winamp to stream songs and manage playlists. Playlists can be updated on the fly etc. I use winamp DSP plugins for volume leveling and crossfading. Using winamp gives you tons of flexibility because of all the plug-ins (remote control, CDDB integration, album art, song catalogs, etc.) I just point rioplay to my PC for the shoutcast stream and that's it.

This has the flexibilty of JRec (maybe more?), but is a bit easier to work with in the Windows XP world.