I'm not so sure there's a K-1 to fight for anymore. Last I saw, neither DREAM nor K-1 has an event scheduled so far this year. Plus DREAM's not been paying all their fighters on time, they even shorted Gary Goodridge several grand after a year without paying him. It looks like FEG's (Fighting and Entertainment Group, DREAM and K-1's parent company) going under.

Also, just saw this from Lorenzo Fertitta
Lorenzo: Strikeforce will continue to use the hexagon. Strike WILL ADOPT the Unified Rules.