Sounds cool. I believe I've seen 'Biometric' btc wallet apps floating around and various hardware wallet implementations. 

Are you the OEM; what is the demonstration/ intended purpose/what determined your design&component requirements? Sounds like a wireless security dongle for mobile or possibly a standalone wallet.

When you ask 'what direction we should go'. Do you mean further hardware development, or are you just looking for programing/applications/firmware for this device?

THis reminded me af a good article (a bit dated) on biometric wallets/banking here:
http://spectrum.ieee.org/biomedical/imaging/the-biometric-wallet