Maybe something like this? What you are asking is pretty generic in nature. The link covers a pressure sensor that has some degree of onboard signal conditioning and is temperature compensated. Honeywell also makes a variety of sensors that could likely be used as well as other manufacturers.
Probably he wants an instrumentation amplifier for the sensors like the one always mentioned by Audioguru: AD620. It looks pretty good.
Otherwise, I've got a friend who uses a Wheatstone bridge and amplified the output using precision op-amps for blood pressure detection. Pretty simple, and very cheap as well. That is if he uses the generic transducers like in hospitals.