I smoke my turkey for Thanksgiving now too but I brine it - no rub required!
It's AWESOME!!!!!!!!!!!!!!!!!!!! The only liquid I use is apple juice then I use brown sugar, kosher salt, lots of garlic cloves, sliced limes, sliced lemons, (squeeze juice out and throw fruit in too) sliced oranges, lots of sprigs of fresh rosemary, sage leaves, and thyme, black peppercorns..........and I think that's about it.
Brine at least 18 or so hours (my turkey is usually 22 - 24 lbs.), rinse off, pat dry, rub down with olive oil and put that baby in the smoker. It took I think about 20 hours last year and was worth every minute! Keep apple juice in the water pan too.
HOWEVER, if a rub is all you want I use:
Personally, I would use a rub on my Thanksgiving turkey.
Save the rub for your beer butt chicken or turkey during the year.