Our 100+ yr old house currently has 3 separate forced hot air
gas-fired heating units.

We would like to add central air sharing the same ductwork and
blowers.

The "traditional" approach would be to add a separate
compressor/evaporator for each of the 3 heating units.

I have seen that some high end remodels are using a single chilled
water unit to supply coolant to multiply blower units and that this is
somehow "better".

Can anyone comment on the pros/cons and appropriateness of using such
a system residentially?

I am particularly interested in comparing initial cost (equipment &
installation), efficiency, noise-level, and reliability.

I will be hiring a reputable HVAC contractor for the installation.

Thanks.