In a large saucepan, combine the white wine vinegar with the water, sugar, mustard seeds, bay leaf, 1 tablespoon of whole peppercorns and 2 tablespoons of salt and bring to a boil to dissolve the sugar. Put the diced peaches in a large, heatproof bowl and pour the hot brine over them. Let the peaches stand for 1 hour, then refrigerate them for about 30 minutes, until the peaches are chilled.
Meanwhile, in a small bowl, combine 1 tablespoon of the oil with the chopped sage, coarsely ground pepper and 1 tablespoon plus 1 teaspoon of salt. Rub the mixture all over the chops and let stand for 30 minutes.
Preheat the oven to 400°. In a large ovenproof skillet, heat 1 tablespoon of the oil until shimmering. Add the chops to the skillet and cook over moderately high heat until browned, 3 minutes per side. Transfer the skillet to the oven and roast for 5 minutes, until an instant-read thermometer inserted in the thickest part of the meat nearest the bone registers 145°. Transfer the chops to a plate to rest for 10 minutes.
Meanwhile, in a medium skillet, heat the remaining 1 tablespoon of oil. Add the sage leaves and cook over moderate heat until crisp, about 1 minute per side.
Put a pork chop on each plate. Using a slotted spoon, top each chop with about 1/2 cup of the pickled peaches. Garnish with the fried sage leaves and serve.