I have a new two story home of approx. 2800 sq.ft in South Jersey under construction. We have a choice of two hvac systems one for each floor with separate supply and return trunks in the basement. One is 60,000 BTU and the other is 80,000. The other choice is a single 100,000 BTU with split supply zones and one return truck to which all return ducts are attached with a bypass damper. One zone is the 2nd floor and other is the first floor with electronically controlled dampers operated by the thermostat on each floor. Which system is a better quality for control, comfort, efficiency and maintenance? Thank you