Internet Radio Broadcasting - Best Audio Software?

I'm in the process of rebuilding a PC for a client who does online Internet broadcasting of a radio show that includes music and voice. Sine this includes a fresh reload of XP, she's also wondering what the best broadcast mixing software programs are.

In the downloads section of MG, I've seen suites including Jet Audio, Audacity and others. She's been having issues with the Creative Labs suite overmodulating (even when the digital meters aren't "in the red") and wants to try something better.

Any thoughts or experience? Thanks in advance for your help.

 

I use Audacity.

Took my a while to work through the learning curve though.