Hi- I'm building a 2400 sq. ft. home near Lexington,VA. 2 story, 9' ceilings 1st fl, 8 on 2nd, full basement, open floor plan on 1st fl, BR's upstairs. Since I currently live in New England I have no experience with heat pumps. We keep our current house, which has hydro air/oil heat(new construction) at 68-70 in the winter and the a/c at 78-79 in summer. The builder's HVAC person suggests heat pump w/propane backup. I've read a lot on this forum and Fine Homebuilding to get some basic info.

I have 2 questions.

#1 Some people say the air from a heat pump system feels "cooler" than air from an oil heat system and a neighbor in VA who has also used oil heat confirms this. So, is the answer to that to just go to the backup propane sooner as the temp goes down?
Would I be able to use the propane backup system alone if I'm not happy with the heat pump? Or is it sized smaller because it's for backup? I haven't spoken to anyone down there who suggests just doing an oil or propane system alone.

#2 It's clear the installer is critical to getting a good job done. Is NATE certification any indication of a good installer? (The closest co. on the Nate site is 50 miles away) What about sizing using Manual J? The first 3 hvac companies I spoke to said they don't use Manual J for sizing unless there are unusual factors. I can get references but everybody has someone who liked their work. Should I start with people who install good brands (whould you say Rheem/Trane?)?

Any help would be appreciated.