i think the dragon has the pump types... even though you must supply the pump
its not incorporated into the machine.
the probe chillers seem like t hey could be a real pain in the ass. the probe isnt long, meaning the heat exchanger will have to be in the room with your grow... one more thing puking out heat and taking up floor space.
at least the external types you can put wherever and pump the water to them...also the external types have plugs on the back to control a heater and uvb purifier for the water also.
no idea if the probe types have those features.