I am currently building a new 2900 sq ft home in North Eastern PA just north of Allentown. The home will have R21 Batt insulation in the walls, R 38 in the ceiling, air sealing and high performance triple pane windows. The house has 9' ceilings and with a 2 story living room and foyer. The home volume is approximately 35,000 cubic ft. I had a manual j calc done and it came back with a 44,000 Btu heating load and a 22,ooo Btu cooling load. If I decide to include the 1,800 sq ft basement which is insulated with R-10 the heating load increased to 54,000Btu and the cooling load went to 22,500 BTU. I am trying to decide which unit would work best. I got quotes on everything from a 2 ton unit to a 6 ton unit. Each contractor feels they are sizing the unit properly. I would like to use Waterfurnce 5 series or 7 series . Any help would be appreciated?