WinAmp is freeware (except for the pro version, but you don't need that).
You can get PeerGuardian2 from http://phoenixlabs.org/pg2 (it's free). It will run each time you boot up and blocks you from accessing any IP address associated with lots of different groups... it will also block them from being able to connect to you, as well, which means that they can't even see what you're sharing. The good thing about PG2 is that it works at the OS level so will work for any and all of your P2P apps. The downside to it is that you may sometimes be blocked from connecting to things like the gov.au websites. Simply right click the icon in the tray and disable it for the time you need that access. For what it's worth, it normally won't block port 80 to the IPs in the list... I would suggest doing so, though, just to be safe. Again, this can be disabled / enabled at runtime.
SafePeer for Azureus you can get from http://azureus.sourceforge.net/plugin_details.php?plugin=safepeer . I believe the new version of Azureus has a way to install plugins from directly within the app itself, so that might be easier. Anyway, it blocks suspicious IP addresses, too... it's good to use the two together.
Fro: hopefully that helps. If, however, you were talking about where to find FLAC files, well, I can't help you. I only ever use Bittorrent to download Linux distributions 🙂