Dave, The two stage will work just fine as will the variable speed that
ramps. The main difference is that the gas valve will ramp along with
everything in the unit from one speed to the next and back with the
variable speed unit. The two speed will run one speed or the other and
switch between the two. The two speed will save a little fuel as where
the two speed variable might same extra electrical cost and repair down
the road. They both will save you a ton in electrical cost compared to
a regular units.
........................bob
