Just curious, as a handheld is on my radar, are you sourcing the keyboard from something off-the-shelf or building a custom one?
I bought one recently just to play round with (http://www.riitek.com/product/259.html), and it's... okay. It would really benefit from some bumps on the FJ or DK keys.
@RL_Dane yes this is a modified Rii keyboard but we’ll design our own custom keyboard in the future prototypes