Thanks for the reply,
I considered the option of passing through the screen and controlling everything through PC, but I hoped to create a more elegant solution.
I looked at the raspberry Pi or an Arduino, but they seemed bloated with features I didn't want.
Your suggestion of 'Devkit8000' looks promising, software is no issue for me, any excuse of a new project
It would be fun to have the keyboard run like a mini PC, that might be worth the effort itself hehehe.
I might just take the plunge on something.... I've helped a few friends with PI projects so could be a good route.
So the Teensy is only good as far as Keyboard (and LEDS?) would it be best to keep that a separate part?