Thanks everybody for the quick replies!
To clarify, I am keeping my American Std furnace.
I will need a new unit for the 2nd story addition. I am happy with the Amer Std that was put in. I was thinking of going with the Freedom 80 Two Stage with Variable DC motor.
My thoughts were that since I have a 80 below and heat rises(so they tell me :-)) that an 80 would make sense. Plus from what I read, the variable motor really helps on the cooling side per Amer Std info.