1. Combine milk and eggs in a large bowl; stir with a whisk. Add fish, and toss gently to coat. Place panko, 1/4 teaspoon salt, and 1/4 teaspoon pepper in a large zip-top bag. Add fish to panko mixture; seal bag. Shake bag gently to coat fish.
2. Heat a large nonstick skillet over medium-high heat. Add 1 tablespoon oil to pan; swirl to coat. Add half of fish; cook 4 minutes or until done, turning occasionally to brown all sides. Repeat procedure with remaining 1 tablespoon oil and remaining fish.
3. Combine sour cream, mayonnaise, pickles, capers, remaining 1/8 teaspoon salt, and remaining 1/8 teaspoon pepper in a small bowl. Serve sauce with fish.