1. Whisk together buttermilk and hot sauce.
2. Place catfish in a single layer in a 13- x 9-inch baking dish; pour buttermilk mixture over fish. Cover and chill 8 hours, turning once.
3. Combine cornmeal and next 6 ingredients in a shallow dish.
4. Let fish stand at room temperature 10 minutes. Remove from buttermilk mixture, allowing excess to drip off. Dredge fish in cornmeal mixture, shaking off excess.
5. Pour oil to depth of 2 inches into a large, deep cast-iron or heavy-duty skillet; heat to 360°.
6. Fry fish, in batches, 2 minutes on each side or until golden brown. Transfer to a wire rack on a paper towel-lined jelly-roll pan. Keep warm in a 225° oven until ready to serve.
*All-purpose flour or plain yellow cornmeal may be substituted.