I am waiting for this exact combo. I have the AKG1000's, the RKV has yet to arrive (this Thursday will be 4 weeks since it was shipped) and the Stefan Audioart cable is suppose to be ready on or before 11-2-02. Fortunately the AKG1000's work great with the Grace 901 and I have already terminated the stock cable with a Switchcraft 1/4" stereo plug.
I got the Stefan AudioArt K1000 headphone cable and use it with an AKG 1000 headphone and an ASL AQ-1005DT amp. After burning in the cable for about 80 hours it sounds wonderful (before burn in it sounded terrible), but now I can't hear any difference between this cable and the stock cable that came with the K1000 headphone. I'd sure like to know whether anyone else can hear a difference.