As long as you're careful with your finish temp, maybe 155 and let it rise 5 degrees in the foil while resting, you'll still have a moist product. Brinning gives you the saftey net of letting the temp get a little higher, but still not drying out.
I just use any poultry rub and, of course, give the breast a good oil rubdown, first.
Be careful on the amount of smokewoood, 'cause fowl can adsorb it readily. I most often use a couple of chunks of pecan.
Paul