Well thanks for all the input.
I was going to go for the resistive bridge, with a high impedance, but then realized this may not work with the impedance of the ADC. For now I’m thinking the amplifier may be the safest solution…
By any chance would any of you know where to find the impedance of the ADC on the LPC2129? The user manual does not provide that many insights on the electrical characteristics of the device.