In a large bowl, add the sweet potato, pineapple, celery, onions, and cucumber. In a small bowl, whisk together the mayonnaise, sour cream, pineapple nectar or juice, ginger, jalapeno pepper, cilantro, salt and pepper. Fold the sour cream mixture into the potato mixture well. Cover bowl and refrigerate until serving. Before serving, sprinkle the toasted coconut and macadamia nuts over the top.