Built my house a year ago, went with R5 continuous exterior insulation + R21 cavity with ducted Mitsubishi Hyper Heat pumps. Make sure your HVAC contractor knows what he's doing, mine didn't and the units are more than double the BTUs I need. This results in the system cycling a lot & crazy electric bills (last month $660) for heating only 2200sf... Otherwise it's a way better system purely because you never even notice when it's running unlike a furnace. The fans can be set extremely low if you buy a good unit.