Whisk together the marinade ingredients - buttermilk, 1/2 cup hot sauce, cayenne pepper and smoked paprika. Place the chicken breasts in a gallon-sized zippered bag. Pour the marinade over the chicken and seal the bag. Allow the chicken to marinate in the refrigerator for at least 4 hours or up to 12 hours.
Heat a gas grill on high. Scrap the grill grates clean and turn all the burners to medium-low heat.
Whisk together the basting sauce ingredients - vegetable oil, honey, remaining hot sauce, red pepper flakes and salt.
Grill the chicken on the first side for about 5 minutes. Flip and baste the chicken with the sauce.
Continue to grill on the second side for at least 5 minutes. Flip the chicken again and baste with the sauce.
Close the lid and continue cooking the chicken until the internal temperature reaches 165 degrees F.
Remove the chicken to a cutting board and allow to rest for at least 5 minutes.
Slice the chicken and serve with garlic bread, pickle slices and more hot sauce.