Florida Fighting Conch really don't fight and the don't get bigger than about the size of a small fist. Queen Conch don't fight either, but the can get to be the size of a small soccer ball and probably wouldn't do well in an aquarium for very long. Both are herbivores and bottom feeders and will work the sand for food.
In SW Florida, along the Gulf of Mexico, we find fighting conch washed up on the beach pretty regularly after storms. I can't say I've ever seen a queen conch washed up. I do see horse conch on occasion. They get as big or bigger than queen conch (longer shell shape) and they will eat other animals, even other conch. The only time I see queen conch is when we go snorkeling in the Florida keys or other Caribbean islands. In Florida they are protected unless you have a proper license.