+1 i've been looking for this awhile tooI love how i answer my own questions sometimes. I ask just a bit too soon.
In the Utilities folder, the Audio MIDI Setup utility has a "Configure Speakers" button under the "Audio Devices" tab. There you can specify which channel goes to which speaker output. Now it won't sould like the high keyboard keys are coming from the low side of the keyboard when using performer perspective stereo width. I wish there could be an AppleScript to change it back and forth quickly and easily, but this will do for now.