K-1 Hao Collection are highly detailed, pvc made action figure. In the collection are Badr Hari, Masato Kobayashi, Mighty Mo, Hong-Man Choi, Ikuhisa Minowa, Kozo Takeda, Genki Sudo and more. You can find these at the K-1 Web Store (Japanese language website).
An older collection includes fighters like Fedor Emelianenko, Bob Sapp, Mirko Filipović, Wanderlei Silva, Ray Sefo, Remy Bojansky, Ernesto Hoost and Quinton Jackson to name a few. These can be readily found on ebay, but at an expensive price as most of them are out of production.