I guess it depends on if you want your cats to go out at all. Is it just the nagging meows that are the problem or the fact that they go out for so long?
If you want them to go out, I suggest a cat door. I am in Florida too. I don't let them out, only on the pool deck. It is safe for them. We live on a conservation area (new word for swamp) and there are birds of prey out there and God know what else. the pool deck is a giant cage. It works well for them. But, I am the constant butler of the sliding door. I have a siamese, talk about your nagging meows!