The PT1000 sounds better then the PT100 with the higher resistance, but the PT100 is less susceptible to noise. You can use 1V across the PT1000 (as long as it is in thermal contact) but the lower the voltage the better. If you have 6 digit meter, you could a 100K range to measure a PT1000 just to minimize the power dissipation.
I tried both and found that PT100 works better for me due to higher noise immunity.
Since a PT1000 (the ones I used) should be driven with max. 0.1mA I did not see any advantage compared to the PT100 driven at 1mA.
I have designed a programmable resistance decade that can "output" resistance values from 1 Ohm to 1.6 M Ohm with a resolution of at least 6 digits.
It was calibrated against a Datron 1271 end of 2017 and is currently doing burn in tests since it has been calibrated.
For what I can tell it's current deviation of it's originally calibrated values less than 0.001% (10 PPM).
However I can only do these checks with a DAkks calibrated 34401A. A more reliable result will be revealed once it is going back to the Lab for a meetup with the Datron 1271.
That decade can simulate all sorts of sensors, like PT100, Ni120, YSI400/700.
It can also simualte water/ salt solutions with temperature compensation (using a second programmable decade as slave to make the temperarure sensor simulation)
Currently working on customisation so you can define "My resistive something" using Excel/Calc, outputting the table to CSV, whack the USB stick into the decade box and import it.
So now you know why I am thinking about a high precision resistance meter.
I need something better than the 34401A but do not want to spend around 10K for that.