Try Solomon Brothers
three brothers from S.Africa own this beautiful store in Buckhead- they're really great and know their stuff (the owners can even cut dimonds if they had to- that's the skill/ talent/ knowledge they have)
http://www.solomonbrothers.com/

or there is a guy in Sandy Springs that I came across~ Mr. French, he is on Roswell Road near the Bank of America/ Starbucks section (if you know where Whole Foods is- I'm thinking the corner of Hammond and Roswell)
he's in a big white building... sorry no specifics- I've got his card at home; he set a new pearl in my ring for me, fast service and good prices and he knows his stuff as well