I would smoke in the 300 degree area if you want a crispy skin and just verify the breast and thigh get to 165. If you brine it will be really juicy and if the chicken is juicy it will not be tough. I would say you would have to really over cook the thing to make chicken tough. If you don't brine it I am sure it will still be juicy as mine usually are. I also agree with RackRat I wold spatchcock the thing.
You can't get where you want to be, if you don't understand where the trip begins. Master the basic smoked bird first before you start trying marinades, sauces, brines, injections, spritz, moping, etc etc etc......
its really hard to do a time temp as there are so many considerations to take into account. Since no one here wants to be responsible for making anyone sick we use USDA guidelines which are based around the internal temperature (IT). Chicken's recommended IT is 165 degrees. How it is obtained is a matter of type of cooker, environment, chicken, coals or element, even how many time you open the pit. You can see the problem of me telling you a 6 pound chicken at approx. 275 degrees should take 2 to 2 1/2 hours. I live in the south (although it doesn't seem like it today) you may live in NYC, see what I mean? Just look at the difference between Oxford and Ocean Springs.
We always go by IT just to insure no one gets sick, we would never want that to happen.