looking into purchasing 5 series NSW 500Wii water to water from waterfurnace. in the instruction manual, it states that an external controller is necessary for operation (page22) it lists 4 options: HydroStat, HydroZOne HZC, HydroZone HZO, HydroLogic Its confusing, I did find the HyroLogic manual but other than that there is no information about this on the waterfurnace website. Anyone used the HydroLogic? Pros and Cons? Im not sure i understand the differences between the HydroZone HZO and the HydroLogic As we will have radiant flooring, desuperheater and air handler - would the HyroLogic be the best option?