Preheat the smoker. Hickory chunks are preferred smoke-medium. Smoke the breast for about 5 hours at 220 degrees F (or until the internal temperature reaches 165 degrees F).
De-seed the chipotle peppers, and cut them into strips.
Remove the breast from the smoker, and season it with more Guajillo chile powder. Warm the tortillas in a skillet. Slice the meat thinly against the grain, and load up burritos with veal and chipotle strips. Squeeze lime juice over the fillings in the burritos. Spoon green salsa over them - if desired.