If you need to amplify a transducer's output, it may be easier to use a different transducer with a built-in amplifier. For long cable runs, or areas with high electrical noise, a milliampere or frequency output is desirable. For environments with very high levels of RFI or EMI, you will need to consider special shielding and filtering in addition to milliampere or frequency outputs. The type of output desired may determine the excitation voltage you need. Many amplified transducers have built-in voltage regulators and will operate over a wide range of voltages from an unregulated power source.
Some transducers are ratiometric and require a regulated excitation.
The power available may dictate whether you use a regulated or unregulated transducer. Consider the trade-offs between the available excitation and system cost. Once you have shipped your product to your customer, the cost of field calibration can be very high. If the transducers are truly interchangeable, you should be able to replace a transducer in the field and expect the system to stay within specification. It is important to discuss long term stability with the transducer vendor.