Preheat grill to medium heat; grease grates well.
In medium bowl, toss chicken with oil and taco seasoning until coated.
Grill chicken, turning once, for 10 to 12 minutes or until chicken is cooked through and instant-read thermometer registers 165°F when inserted into thickest part of chicken. Let rest for 5 minutes. Using 2 forks or your fingers, shred chicken. Transfer to medium bowl and toss with 1 tbsp lime juice.
Warm chalupas in pan according to package directions.
In small bowl, stir together sour cream, chipotle pepper, adobo sauce and remaining lime juice until combined.
Divide chicken mixture among chalupas and top with sour cream mixture, lettuce, pico de gallo and cheese. Serve with lime wedges.
To promote even grilling, use meat mallet to pound chicken between 2 sheets of plastic wrap to even thickness.
For a variation, substitute taco seasoning with tajin seasoning to taste.