Steady state cardio and HIIT will both shred fat, as long as the cardio is minimal effort (fat burning zone - specific heart rate to aim for) for long durations, but neither will work very well unless you smash some weights in the same session to spike your metabolism. In terms of what way to train, it doesn't really matter. Strength training, hypertrophy, and endurance training will all get you shredded as long as you follow a caloric deficient diet (cut out carbs as much as possible). Smash down some steamed spinach and tuna for dinner instead of rice... the carbs from the sweet potato should be enough to get you through your daily exercise whilst cutting body fat. Good luck.