Akainu, Aokiji, Kizaru, Greenbull, Fujitora, Garp, Sengoku, Smoker later, Coby later, Zephyr, and Kong.
They'll all have conquerors haki. Just like King will, BB will, Shiryu will, Beckman will, Lucky Roo too probably, etc....
BB may even have more than 2 conquerors users on his crew.