Very rare to see them in any aquarium. Not that they are rare in the wild, just rare to get your hands on for aquarium. I've read reports stating that they can grow to 5 lbs in their first year of life. That to me would be around 18-24". Good luck.
they're not illegal at all and exempt from ILFA licensing requirements. I have never seen one imported from the states though in more than 20 years of fish keeping - I suspect that the restrictions are in place in the US rather than over here.