Preheat oven to 400°. Coat baking potatoes with vegetable cooking spray; pierce potatoes several times with a fork. Bake 1 hour or until tender. Remove from oven, and cool slightly (about 10 minutes). Cut off top one-third of each potato, and reserve for another use. Carefully scoop out pulp into a bowl, leaving 1/4-inch-thick shells intact. Stir together sour cream, vinegar, minced garlic, coarsely ground pepper, spicy brown mustard, salt, sugar, and hot sauce. Stir pimiento, 3/4 cup sour cream mixture, chopped pickles, and green onions into potato pulp in bowl. Reserve remaining sour cream mixture. Spoon potato mixture into potato shells; cover and chill 1 to 24 hours. Divide chicken, cooked and crumbled bacon, and shredded cheese; top each with reserved sour cream mixture.