Thank you for this tip! I knew that lighter-bodied birds like Leghorns tended to be better for warmer climates. Heat is the big issue here - I think I only had to break ice in my horses' water tank about half a dozen times last winter. I'm planning on placing the coop in the shadiest portion of my property and using a fully covered coop/run design with lots of wire for air flow. I'm hoping to make the run portion secure enough to not have to lock them in the coop portion at night.
The only breed on my list that I'm a bit worried about handling the heat is the Buff Orpington. I know people down here who have raised them successfully, but I'm a bit apprehensive. They're so pretty, though, and have such a great reputation for docile personalities, that it's hard to rule them out completely. What do you think?