Stir together kefir, vinegar, honey, 3 Tbs. of the oil, and 1/4 tsp. of the pepper in a large bowl. Add coleslaw and sauerkraut; stir until evenly coated. Chill, uncovered, 30 minutes.
Meanwhile, stir together smoked paprika, garlic powder, salt, and remaining 1/4 tsp. pepper in a small bowl. Sprinkle mixture evenly over pork chops, pressing to adhere.
Heat remaining 1 Tbs. oil in a large skillet over medium-high. Working in two batches, add 2 pork chops to skillet. Cook until golden brown on both sides and a thermometer inserted in thickest portion of meat registers 135°F, 4 to 6 minutes per side (temperature will rise as pork rests). Remove from skillet and cover loosely with aluminum foil; let rest 5 minutes.
Place 1 pork chop on each bun bottom; top each with 1/2 cup coleslaw mixture. Replace bun tops. Serve with remaining coleslaw mixture.