Back in 2007, I co-founded a startup to do something similar to this. Check out "System 7" @ http://www.kylecherry.com/ for what it looked like (I can't find examples of the software.)

We didn't succeed for non-technical reasons & died before getting to market. But here's my advice:

- go with Linux or BSD, not Windows (maybe WINE or something similar if you must run Office) - prototyping and fabrication is non-trivial - we worked with iSuppli and it was worth every penny