I live in the north central part of FL and our weather goes from about 100 in the summer down to an occasional freeze in the winter. You didn't say what part of FL you are moving to, so if you're going farther south, you won't have the freezes in the winter (we get 2-3 a year).
Australorps are good all-weather chicken. They originated in Australia is my understanding and they tolerate heat and cold very well. I've had them in the past and they did great with the weather.
I've never had the BO's so can't give you any first hand experience with them.
I currently have Barred Plymouth Rocks, Red Sex Links, Speckled Sussex, Rhode Island Red and Easter Egger.
They all have done well for us with our weather. Birds can keep themselves warm better than cool (all those feather coats, you know). In the summer, it takes some effort on our part to keep them comfortable but it's not impossible. You have to watch them, when they hold their wings out to the side and pant that means they are warm and are trying to cool themselves off.
We combat the heat by doing several things such as:
* Lots of shade, both natural and man-made
* Lots of fresh water (extra waterers and frozen water bottles in them)
* A large shallow pan of water then can stand in (some use kiddy swimming pools, my girls wouldn't go near it)
* Frozen or cold treats like melon, grapes, cucumbers
* Lots of ventilation in the coop
* Our coop has 2 doors opposite ends & we replaced the solid doors with hardware cloth screen-type doors for summer
* Box fan in the coop circulating the air but not blowing directly on them
Hope some of that helps!
