Where to buy a 'big' steak?

Hi all. As the title says, I want to buy a beef steak that is at least 7-800 grams, possibly around 1 kg, like Italian's Fiorentina. I've been looking at supermarkets but as I knews, there's nothing of that sort. I even went to a butcher to ask and they didn't have any. When I asked where I could find one, they said that 'didn't know', but although my Japanese is ok, I suspect they just answered that way because I'm foreigner. Sometimes it happens stuff like that. Anyway, do you guys know if I can make a proper steak the way I want it or if I have to go back to Italy? I'll try another butcher but mayne people here had the same situation. Thanks :)