Hi there! I'm new as well & also live in the South. I don't have any chickens, but I am raising ducks for the first time ever. I hadn't considered the heat posing a problem with laying, but I'm glad you said something about that so now I know to look out for this!
I have 3 black lorps in North Florida but this will be first summer
They are in a Coop with a tarp on the backside so shade or sun if they prefer I guess