Will: Not being from Georgia, I will do my best to help you. After looking at many resources, the best choices for broadcast seeding of grass is the ryegrasses - perennial, annual or even winter rye and/ or tall fescue. The only problem for you living in central Georgia is that the ryegrasses will survive your summers very well, but they establish easily. Tall Fescue is a little harder to get established but should thrive in your area. If you are planning to use this seeded area for pasture, please seed a "novel-endophyte" variety of tall fescue. In your part of the world, you need to get this area seeded as soon as possible. If it were me, I would seed a mixture of perennial ryegrass and tall fescue. Using the U. of Ga. recommendations I would broadcast seed: 20+ pounds of tall fescue seed plus 2 pounds of perennial ryegrass seed per acre. U. of Ga. has a good factsheet on Tall Fescue at:
http://www.caes.uga.edu/commodities/fieldcrops/forages/species/GeorgiaForagesTallFescue.html 
