Frisco, The boneless, skinless chicken breasts work fairly well in the smoker. I do them all the time, usually when I have my smoker going for something else. Brineing is good.
I try to go about one to one-and-a-half hours at low temps-around 225 on the breasts. Start them direct from the fridge, this wil help slow down the cooking and give more time for smoke flavor to develop. If they are brined, they are somewhat forgiving and will turn out moist iven if a little overcooked. I shoot for a internal of 160-165 maximum, which gives me a little headroom on reheating.