cmbb, you might check out Kellyco's Accusound for $59.95. Catalog #801-132795
The impedance is 90 ohms with a frequencey range of 17-20,000 Hz. It has a sensetivity of 100dB/1mW and has a lifetime warranty along with individual vol. controls. I believe that they come with a 1/8" jack and have a 1/4" adaptor. Whether they're stereo/mon switchable, I'm not sure.
Just a possibility.