Hi, I’m an industrial designer starting an arduino project that records sessions of motion data.
so you wish to build a data acquisition board using an Arduino?
What sort of input? (8 bit digital, data strings like GPS, analog, etc)
How many channels(sensors)?
What sampling frequency?
How many hours worth of data needs to be stored at a time?
There are many datalogger and data acquistion projects out there. Google is your friend, as is Sparkfun. 
Interesting project.
Im trying to build several different versions.
Are you looking for a finished project or a box with a bunch of jumper wires strung about to breakout boards?
yes that could definitely be a good version for impact sensing in a jacket or other gear. Please send me a message if you want to take this further and get directly involved with my project. That also goes for anyone else who knows how I could achieve different motion sensing devices.
I also have a question. Are arduino’s something that can be integrated into a product and sold on my site? Or would they just be working prototypes?
Yes, yes, yes. I know of some people who have integrated an arduino into a finished product because of ease of design and reprogram ability. On the other hand, it is ment as a prototyping tool.