I like the idea of the alternative fingerings and the accelerometer. I have a Yamaha WX5 which uses four octave buttons, two above (octaves up) and two below (octaves down) a thumb rest. By covering either or both of the octave buttons it gives a range of +- 3 octaves, but it can be difficult to play and glitches if you accidentally slip off one. I believe the Akai EWS controllers use an octave wheel, but haven't played one.
If you haven't seen it then Patchman Music http://www.patchmanmusic.com/ has some great wind controller ideas and resources, and some absolutely stunning audio demos Patchman Music TURBO VL Upgrade Chip for Yamaha VL70-m (scroll down a bit).
Good luck with the project!