FAQ:

Q: What supplies do most customers run?

A: Allmost all customers use a current source. Many 1 mA, but some also 0,18 and 0,25 mA

Q: What would be a recommended opamp and amplifier to use in the electronics?

A: For the lowest noise and good precision, an LT1678 would be an excellent opamp. If you need lower power but still good noise performance, an LTC6078 would be a good choice, and maybe an LT1789 as an instrumentation amplifier.

Q: Can you recommend some electronic components that can be useful in our design?

A: You could check out LTC6084, LTC6081, LTC6087, LTC1128 and LTC1028. And LTC1167 instrumentation amplifier. An expensive but very precise reference (this expensive one is more meant for testing purposes) is the LT2100. You could also check next A/D convertors: LTC6655, LTC2379, LTC2442.