If you are portraying a unit fighting at Ringgold Gap then you will need a battle flag from Cleburne's Division as that was the only Confederate force there. This is a blue flag with a white circle and white exterior borders. Longstreet's Corps was not at this battle as they had been deatched into Eastern Tennessee by this time.
Please make sure that the flag you use for the battle is accurate to the battle.
In terms of the 16th Georgia's flags, getting the Georgia flags book from the Georgis Capitol Museum will not only help you with making a flag of that unit but will also help the conservation of these flags for all-time. The $20 for the book is a small price to pay for them. Please help these flags.