The timing is always difficult to judge, when using the Bradley. Cooking two at once will take longer than cooking one, because the recovery time will take longer. So maybe add about 30 - 45 minutes more than your test run.
When I use the Bradley to smoke/cook chicken, I cook at 240°F (I have a modified dual element). Apply no more than two hours of smoke. Preheat your Bradley to 250°F with the vent 1/2 open. After loading the chicken, fully open the vent, and cook at 240°F (you may not reach that temperature before the chicken is done). I generally use apple, but maple and pecan works just as well.
To shorten the cooking time butterfly (spatchock) the chickens. I like to quarter the chickens, or use chicken parts. They will cook faster, and you can separate the white meat from the dark, by placing them on different trays. Leave the chicken out at room temperature for an hour before placing them in the smoker.
If you have the time and refrigerator space, air drying the chickens for a couple of hours, does help a little with the skin, but it is always best to finish them with high heat, such as using a grill, or under the broiler of you oven. If the chicken is done early, you can use the kitchen oven as a food warmer. Preheat the oven to 225°F, after placing the chicken the oven, turn the oven off.