Rauf,

The following are possible economic uC boards you can use:

For $130 US:
http://www.axman.com/Pages/neuprod8_cme0552.html

For $115 US:
http://www.axman.com/Pages/neuprod8_cme0562.html

They both have 8 channel ADC but its only 8bit resolution. There is a prototyping area on the board so you can add the current to voltage conversion.

You can order online. I know one of the owners but I have no investment in the company. They switched to Motorola processors and have these 8051 designs left over from their first year in business. For 8051s, they appear to me to a bargain. They use EPROM for program storage though.

To protect your interest in the project, you might buy whichever board and etch away all logos and names of the company that produced it. That was they are more likely to involve you in any future systems.

Another idea in this area is to use the onboard EEPROM and to load it with a datablock. Program the EEPROM with one EPROM you don't supply them and then on the EPROM you give them, have it check the EEPROM for the right pattern. You can use a few programming techniques to make it harder for them to decode what you're doing. This would mean that if they bought a new board from the same vendor, copied the EPROM, it still wouldn't run because the EEPROM didn't contain your secret datablock.

That would be some additional job security.

aka J