Not ready to donate, but I would make a down payment on a pre-order if the project reaches that phase. I suggest starting with the simplest possible model.
If you noticed the part in phase 3 about how the core parts of it would be hardware agnostic.
The way I would go about it would be to select a chip series, and then to develop the software on a devel board from that series, and then create the hardware and tune it to the hardware. This is what we're probably going to do. There is, in fact, a cheap (in comparison to multi-thousand dollar eval boards) devel board for the chip series I have chosen.
I see no justification for all these models. There are no marketing statistics nor any marks of viability. I wouldn't invest a penny into this.
The models are just my guess on the range of products I would offer. Im really doing this as a hobby, not as a business venture. Each one would probably be built after the order (of course keeping a decent amount of the core parts around and offering a discount when I would have to delay).
If you don't want to invest, fine, don't. If you want to go in and look at market statistics for me, I welcome you to the project, but for now, Its just a hobby of mine. All the different models are just concepts. I'm probably just going to end having the casio style MyBit, and the standard BitClip, with customization options to bridge the gap between them. Some people prefer the no-frill interface of a fancy calculator, I for one prefer a simple touch interface on such devices. At the very least, I want a keypad and joystick-y-thingy. The point of multiple models is to give the people that don't want to put much into it a low end option, and the people that are willing to pay a premium a nicer, easier to use interface. Hell, I might even pop them all into the same case and just give a choice of interface options shoved into that case.