By the good development practice, the device significantly changes between stages of the development: alfa prototype (which works at your laboratory), beta prototype (which works at laboratory of carefuly selected potential customer), and industrial prototype (which can be sold to any customer).
If your device isn't trivial, producing the board in a 100k quantity will demand an unavoidable deep re-design, possibly including the custom hardware.
Trying to skip the stages isn't a good developing practice.
> The question is: If I will produce 100K board is conviniente buy MODXXX or Is better create
> my custom hardware? For the moment I think that is better base our develpment on MODXXX.
Check option of replacing the microcontroller with the encyption enabled one. NetBurner mention possibility of light customization of their products. The encyption capability isn't included into the standard product due to the export regulations.
> Unfortunately other coldfire offer me useful possibility such as USB and encyption capability.
I havn't the practical experience with SD card.
Some NetBurner carrier board has the SD card connector.
The file system for the SD card is integrated into the standard development environment. The file system is get (free) from another company.
> Just another question. Do you have experience using netburner for manage SD card?
> Are the functionality included in the standard packet? There are some example for hardware design?