the teensy 2.0 can use all the pins.
the teensy 1 has 2 pins dedicated to led's
for the pinouts of the teensy 2.0 go here
http://www.pjrc.com/teensy/pinout.htmledit1:
26 pins total
poker layout = 14 cols + 5 rows = 19 pins
75% layout = 15 cols + 6 rows = 21 pins
this is not counting the led's that you can use the remaining pins for with led's
you also need to look at hasu's firmware for more information.
It is the thread that helped me the most with my alps hardwired keyboard.
http://geekhack.org/index.php?topic=41989.0edit2: I do not know a way to say this in text on a webpage to show that I am not trying to be a **** with this statement but here is a shot at it.
If you do you know anything about coding or are looking for someone to write the firmware for you, I would suggest that you not continue down this path.
If you have a willingness to learn basic code structure in C programming language then I am sure we will help you get the information you need.