I am currently looking into generating a new set of HRTFs; 96khz 24.bit. That should produce the best spatialised sounds out there. Unfortunately I have to interpolate the old set; 44.1khz 16 bit for now. But researchers are generating better quality all the time; it's down to the mics and speakers used, and these guys are using the best.
A lot of folk use headphones with their ipods now, and ambient music has yet to climb up the ranks towards the big boys like, rock. The market is smaller, but the rewards are not diluted over thousands of other grabbing hands. Spatial sound and Ambient seems like a good solution.
otherwise, I'd be synthing it in a rock band like Floyd; just the same dream in the end.
Floyd released a track using holophonics; the proper DSP sound rendering algorithm simulates the holophonic hardware. Not just simple 3D sound.
http://www.apple2.org.za/gswv/1WSW/Audio.4D.html