Multi layout controller for Unicomp?

[staysaneone]

I just recently got a Unicomp Spacesaver 104, and I love it. The problem is, I'm trying to learn Colemak. I could see how a hardware Colemak keyboard would be useful, but I don't want to loose qwerty. After spending a good amount of time on this site, (I've was lurking for a while, you guys convinced me to get this keyboard,) I saw some very interesting mods.

An easy to use controller mod would be awesome. I know that a of the ones posted here are already dead simple, but I think a mod that would make custom layouts easy would be much appreciated.

So my idea was using an arduino (because of the ease of programing to hardware) to make a controller for the Unicomp (or Model M). But if the Arduino won't work, any other controller should be able to. Two dip switches placed somewhere on the keyboard would change the layout.
00:qwerty 01:colemak 10:dvorak 11:custom.

What I need to know is
1. Is this possible?
2. How many pins does the Model M use to connect to the controller?
3. Where could I learn about programing a keyboard?
4. Is anyone else interested in the idea or willing to help?

[Superfluous Parentheses]

IIRC, the USB mod for the Model M (which uses the same controller as the arduino designs) is - in principle - programmable. You might need a switch or two for switching between "baked in" layouts and/or some extra code to make it programmable over USB, but I'm quite sure it can be done.

edit: it'll probably still need some custom code. some experience in C would be nice, I guess, and with that switching the layout via (a few) hardware switches won't be too complicated. USB/software programmable stuff will be a little harder.