In a medium-sized mixing bowl whisk the flour, cornstarch, pepper, and paprika (all of the first coating ingredients) together until well mixed.
Using a separate medium-sized mixing bowl beat the eggs and milk together and place it next to the other first coating ingredients.
In another separate medium-sized mixing bowl whisk the third coating ingredients, breadcrumbs, panko crumbs, and flour together and sit it with the other coating bowls (it's easiest to place them in a row like an assembly line).
Place about 2 inches of oil, about 4 to 6 cups (depending on the size of your pot) in a Dutch oven or skillet with high sides. Clip a candy thermometer to the size of the pot or skillet and heat the oil over medium-high heat until it reaches 375ºF or when the oil sizzles when a few breadcrumbs are dropped in.
Take the shrimp and first dredge it into the flour/cornstarch mixture, then the egg/milk mixture, then into the breadcrumb mixture making sure you fully coat the entire shrimp each time. Set the shrimp aside on a plate or wire rack.
Working in batches carefully drop about 5 to 6 coated shrimp into the oil and fry for about 2 to 3 minutes (depending on size) and flip for another 2 minutes.
Use a slotted spoon or a wire skimmer to remove the shrimp from the oil and place it on a paper towel-lined plate or a wire rack fitted over a baking sheet.
Before adding the next batch of shrimp to the oil make sure the temperature returns to 375ºF. Repeat until all the shrimp have been cooked.