1. Combine sugar and salt in a large bowl; add boiling water, stirring until sugar and salt dissolve. Stir in ice cubes to cool mixture. Add pork chops; cover and chill 30 minutes.
2. Meanwhile, sauté onion in hot oil in a medium saucepan over medium heat 2 minutes or until tender. Add garlic and ginger; cook, stirring constantly, 45 to 60 seconds or until fragrant. Add ketchup, peach preserves, and peaches. Reduce heat to low, and simmer, stirring occasionally, 30 minutes or until sauce thickens. Add vinegar; season with kosher salt and freshly ground pepper to taste. Remove from heat.
3. Remove pork from brine, discarding brine. Rinse pork well, and pat dry with paper towels.
4. Preheat grill to 350° to 400° (medium-high) heat. Pour half of peach mixture into a bowl; reserve remaining mixture. Season both sides of pork with desired amount of kosher salt and freshly ground pepper.
5. Grill pork, covered with grill lid, 5 to 6 minutes on each side or until a meat thermometer inserted into thickest portion of each chop registers 145°, basting pork occasionally with peach mixture in bowl. Remove pork from grill; let stand 5 minutes before serving. Serve with reserved peach mixture.