You aren't going to see in many, if any shops, but thats due to their price and popularity, not that they are especially rare or hard to get. It should be easy enough for a good shop to order one in. Their situation may have changed though with the new IBAMA allowed list but I think their distribution is not entirely in Brazil.
As in2cichlids said, they are nearly always 10"+ in the UK and US but I have seen smaller ones down to 4" on Japanese sites, I guess they command a premium.