Ruhian may not look the part at first, but if you've seen any of his fight scenes (another Raid veteran), literally any of his fight scenes, you'll know. Like Uwais, Ruhian practices pencak silat, but would be performing northern shaolin, the technique of firebenders. Both Uwais and Ruhian could also act as fight choreographers for the series and help train the rest of the cast, ensuring continuity of technique across bending styles.
Secondary Choice: Daniel Dae Kim