In a mixing bowl, combine buttermilk, hot sauce, paprika, garlic powder, onion powder, salt, and black pepper. Add the chicken breasts and ensure they are fully coated. Cover and refrigerate for at least 30 minutes.

In a separate bowl, mix mayonnaise, sour cream, hot sauce, lemon juice, garlic powder, and salt until smooth. Set aside.

Preheat the grill over medium-high heat. Remove chicken from marinade and grill for about 6-7 minutes on each side or until fully cooked and internal temperature reaches 165°F (75°C).

On the bottom half of each toasted bun, place a piece of grilled chicken. Top with shredded lettuce, sliced tomato, pickles, and a generous amount of creamy sauce. Cover with the top half of the bun and serve immediately.