In my humble opinion if you have access to them go ahead, but if you don't you can use regular dumbells, for MMA purposes, giant sets with compound exercises, barbell/dumbel/kettle/ complexes, tabatas, hitting a tire with a hammer, strongman implements too, circuits etc are the best to build stamina and endurance, you are a strong mofo already so you should really focus on these, but still keep an eye out for your squats, deads and pressing strength too. It would be a shame if you as strong as you are lose a fight over lack of conditioning issues.
You want the best? youtube Fedor Emelianenko, Randy Couture those guys are fucking relentless conditioning/stamina machines.