I've been looking at this recently too. I like the basic design of chordite http://chordite.com/ http://chordite.com/ 7 keys across four fingers, and then pe

I've been looking at this recently too. I like the basic design of chordite http://chordite.com/ http://chordite.com/ 7 keys across four fingers, and then perhaps a trackpoint for the thumb. In terms of a bluetooth gpio controller, there are a few options including a few that have been kickstarted recently (e.g. bleduino and rfduino).