I've been using this since I found it on the Weber Bullentin Board a few years ago.
12-lb turkey, brined 24 hours in 1 gal apple juice, 3/4 cup Morton K salt, 1/2 cup honey, 3/4 cup white sugar, 1/4 cup brown sugar. Rinsed the bird VERY well inside and out with running water to remove all traces of the brine.
I'll mix that together over the stove while bringing it to a boil. Once it starts to boil take it off and let come to room temp.
I smoked them in hickory and/or apple/cherry wood in my WSM for 5-6 hours each bird, shooting for a temp of 165 in the thigh.