Check http://www.openstenoproject.org/ - they have some pretty great ideas and alternatives (and the software to run them)

There is a type of stenographic keyboard which is common in Italy and, with minor modifications, I believe you could re-purpose a MIDI keyboard for it. The keyboard is called "Macchina Michela" and the associated method is "Metodo Michela", you can see it in action in this video (the audio commentary is in Italian): https://www.youtube.com/watch?v=uniHoxe6HpY

Stenosaurus is apparently making some progress: http://stenosaurus.blogspot.ie/ .