I had kphonepi working on the Sharp Rom, but could not get it working correctly with pdaXrom RC11 or 12. Also tried unsuccessfully to run kphone. This was some time ago, so I can't post the output. I would be very happy to get any phone client working on pdaXrom.
As for headset - I previously used an old stereo headphone set with the left earpiece working as the mic. It worked surprisingly well !!