I downloaded BroadWave and looked in the settings. Under general, there are some options to adjust the quality levels for the two streams. In the free version, the dial-up stream can be increased to 40 KBPS/16000 Hz, if you go above 24 KBPS for the dialup setting it automatically changes to stereo. The sample rate also automatically goes up with the bit rate setting for the broadband stream. The sample rate and channel settings can't be controled though, only bit rates.
I would suggest using, say, a 64 or 48 KBPS AAC+ stream for lower quality connections. AAC+ sounds much better than MP3 at low quality compression levels, but that format doesn't seem possible with the free version of BroadWave. BroadWave is probably the easiest free streaming solution to set up that I've tried, though.
Can't wait till I am in the area, and can pick KSET up with a radio so I can see how good it must sound on AM. It really is awesome how you were able to get ahold of this station like that.