-Finally, will the boards need to be connected to a computer at all times, or can they save data etc. (how to I put the data on a computer for analysis usb or ethernet shield)?
I would write to a connected SD card.
The primary goal of this project is to design a low cost 1)Arduino add-on module, or 2)"shield", to enable students, hobbyists, and professionals alike to implement precision measuring systems as easily as possible. ...Applications of the Shield... Strain gauges