Combine the smoked paprika, cayenne, celery salt, salt and pepper in a small bowl. Mix to blend.
Combine the chicken and ¼ cup of the Buffalo sauce in a bowl; toss to coat. Toss with the rub.
Grill until the chicken is cooked through, about 15 minutes. Remove and allow to cool. Chop the chicken into bite-size pieces. Set aside.
In a large roasting pan, spread out half of the pita chips in an even layer. Top with half of the chopped chicken, half of the remaining Buffalo sauce, half of the blue cheese topping, half of the chives and ½ cup of the shredded mozzarella.
Repeat, ending with a generous helping of the shredded mozzarella. Place the roasting pan on the center rack of the smoker and bake until the cheese has melted and the pitas have crisped and soaked up some of the hot sauce, 5 to 10 minutes.
Remove from oven and sprinkle the nachos with the celery, radish and jalapeno.