I think, in my case, I'd rather run a water-to-water chiller with an outdoor fan coil for excess heat rejection, than a reversing heat pump type setup. With a water to water, you could run the chiller as necessary to cool the chilled loop and reject to the hot loop, and if the hot loop is over a set temp, run it through the outside coil. This would maximize the ability to recover waste heat from the chiller (and use it for domestic hot water). If hot loop temp is low, it would be supplemented with a high efficiency gas water heater.

With this type of setup, it would be possible to build a 'central plant in a box' type setup, that contained the controls, cold water supply and return, hot water supply and return, and a outdoor (or ground loop) coil supply and return. If gas is an option, it can be installed on the hot loop. In residential uses, I see no reason why you can't use the same loop for heating and domestic, as long as all components are domestic water rated. This type of box can include the pumps, chiller, etc. Accessories such as storage/buffer tanks, etc can be added, as can other items such as solar heat.

There's also no refrigerant work with a box like this. It's a self contained appliance, just like a refrigerator.