Place the potatoes in a large stock pot and cover with cold water. Add 1 tablespoon salt and bring to a boil. Reduce the heat to medium, cover and cook until the potatoes can be easily pierced with a knife, about 10 minutes. Drain the potatoes in a colander, rinse under cold water and set aside while you make the dressing.
Stir together the sour cream, mayonnaise, mustard, vinegar, garlic powder and onion powder in a large bowl. Add the potatoes and gently toss until coated. Gently fold in the bacon and cheese, reserving 1/4 cup of each for garnish. Add salt and pepper to taste. Transfer to a serving bowl and sprinkle with the paprika, green onions and reserved bacon and cheese.