It depends on alot of things as to what is best for you, I need little
Ac since im in shade and my house design and footprint dont allow much
solar heating, my neighbors in sun with a ranch house nearby are always
hot. Will you want it 70f or 78f. Humidity is an issue with high
humidity areas you may want it running alot for just humidity removal.
Most important is you get a written load calculation for sizing and
ductwork, or your system will never be right. You have a choise, pay a
bit more for a 14-16+ seer or pay forever a much higher electric bill,
electricity is going up so think about it. Personaly I shop for highest
efficiency ratings, and have the lowest utility usage of my area.