Preheat the oven to 200°. In a bowl, whisk 3 tbls of the kosher salt with 2 tbls of the pepper, the olive oil and the minced rosemary, thyme, sage, bay leaves and garlic. Rub the mixture all over the chickens and set them in a roasting pan. Roast for about 2 hours and 30 minutes, until an instant-read thermometer inserted in the inner thighs registers 150°. Let the chickens cool, then cut each into 10 pieces. (You should have 4 drumsticks, 4 thighs, 4 wings and 8 breast quarters.).
In a very large bowl, whisk the buttermilk, with the hot sauce and sugar. Add the chicken pieces and toss well. Cover and refrigerate for 1 hour.
In a large saucepan, heat 2 inches of grapeseed oil to 375° with the rosemary, thyme and sage sprigs, the 5 whole bay leaves and the head of garlic. When the herbs are crispy and the garlic is golden, transfer to a paper towel-lined plate.
Meanwhile, in a large bowl, whisk the all-purpose and rice flours with the garlic and onion powders. Whisk in the remaining 3 tbls of kosher salt and the remaining 2 tbls of pepper.
Remove half of the chicken pieces from the buttermilk, letting the excess drip back into the bowl. Dredge the chicken in the seasoned flour, patting it on lightly so it adheres. Fry the chicken over high heat, turning occasionally, until golden and an instant-read thermometer inserted in the thickest part of each piece registers 160°, about 6 minutes for the breasts and 8 minutes for the wings, thighs and drumsticks. Transfer the fried chicken to a paper towel-lined baking sheet to drain. Let the oil return to 375° before you coat and fry the remaining chicken. Transfer the fried chicken to a platter and garnish with the fried garlic and herbs. Sprinkle with flaky sea salt and serve right away. with lemon wedges.