I live just west of Atlanta Georgia and in the process of finshing approx. 750 sqare feet of attic space. It is basically two rooms. One is over the garage and the other is over heated and cooled space. I plan on putting a lot of care and money to make sure it is insulated properly to make it as air tight as possible. I just got my first estimate today. The gentleman was referred by a friend of mine and has many years in the business. He walked me through the plan and explained everything to me. He told me that the room over the garage was going to need the most air due to the unfinished garage and the heat of the roof. He quoted me a price for a 2.5 ton unit. I spoke with another professional about the tonage and he thought that was to big seeing that it is 1 ton per 300square feet. The gentleman that quoted me the job also told me that he is not a big fan of flexible duct work and always builds is on rigid duct work. Does this sound like an over kill on the tonage or is it about right. He also quoted two prices. The first one with a 13 seer rating and the next with a 14 seer rating. The 14 seer rating was 1000 dollars more and came with a variable fan handler. Any suggestions. I will be getting more quotes. I need to know if a contractor quotes me a 1.5 ton than I don't need to use him. Thanks for you advice.