Whisk the vinegar, 1 cup water, 3 tablespoons salt and 1/2 teaspoon pepper in a medium bowl until the salt is mostly dissolved. Pour the liquid over the wings in a large nonreactive bowl or baking dish and submerge the wings. Refrigerate, stirring occasionally so that all the wings are coated, 2 hours.
Drain the wings. Pat dry and let come to room temperature. Preheat the oven to 200 degrees F.
Set a rack on a baking sheet. Fill a large heavy pot halfway with vegetable oil; heat over medium-high heat until a deep-fry thermometer registers 375 degrees F.
Whisk the flour, cornstarch, 2 teaspoons salt and 1/4 teaspoon pepper in a large bowl. Whisk in 2 cups very cold water to form a light batter. Add the wings to the batter and stir to coat. Lift out the wings one at a time, letting the excess drip back into the bowl.
Working in batches, fry the wings: Using tongs, lower the wings into the hot oil and hold for a couple of seconds before letting go to seal the coating. Fry until golden and crisp, 8 to 9 minutes. Remove to the prepared baking sheet, sprinkle with salt and keep warm in the oven while you continue. Serve with assorted sauces.