Yikes, mentioned by name. Uh, all I have is the American PS port, so I don't know how it stacks to the Japanese PS port. I don't think anything was removed (from the japanese PS); at least I've never heard of anything. It's a fun little game with an engine somewhat similar to the Real Bout engine, with combination arts, the same button layout (punch, kick, heavy attack, line sway), etc. There are some combos that were in the Hyper version that are missing in the PS version, and the backgrounds are severely watered down from the Hyper version. On the other hand, being able to play as Duck and Ryo is a lot of fun, and the opening movie is very cinematic, and although dated, it's a must see for Fatal Fury fans. I'd recommend it -- any version you can get.
Actually, I think I'll go have a game right now.
edit: oh yeah, where can you get it...? I got mine from Chai, who traded someone else on these boards. I've seen a few on eBay here and there (in fact I see one right now with a BIN of $19.99. I've also seen one (way overpriced at about $30, but...) a couple months ago at GameDude here in CA. GreatKiller, a member here, works there. Maybe you could ask him if it's still there.