9 seer possible, 700$ alot of waist. Why go with 13-14 seer , you can go
up to 19.5 seer. Trane has a Seer Comparison Savings Sheet on their
site. I believe 14 seer might cut your bills in half, a 19 seer wont cut
your bills as much as the increase to 14 seer did as the savings are not
linear, they decrease as each higher seer is used. You can also save on
using a VS DC blower motor on a new furnace, apx 25% in electrical over
a regular AC blower. But get the 10 yr warranty. I would not stop
looking with Rheem but check out what else is offered by other
companies. Yes you need a load calculation, and duct test. But also
consider your building, windows and insulation, im sure you have alot of
room for improvement.