Combine first 5 ingredients; reserve 1/4 cup marinade. Combine remaining marinade and chicken in a large zip-top plastic bag. Seal and marinate in refrigerator 3 hours, turning occasionally.
Remove chicken from marinade; discard marinade. Place chicken on grill rack coated with cooking spray, and cover and grill 10 minutes on each side or until done.
Heat oil in a large nonstick skillet over medium-high heat. Add bell peppers and onion; sprinkle with seasoned salt. Sauté 4 minutes or until tender. Add reserved 1/4 cup marinade, and cook 2 minutes. Cut chicken into thin slices; add to vegetable mixture.
Place a 10-inch cast-iron skillet, upside down, over high heat for 1 1/2 minutes. Turn pan over, and add chicken mixture. Warm tortillas according to package directions. Serve chicken mixture immediately with warm tortillas, salsa, and sour cream.