I use a hook through the cavity with a big pot. The size of the pot doesn't matter to me - the fire does though. If the temp outside varies (or the wind is blowing) or it is extremely cold, take several readings with a thermomoter before dunking the bird. You don't want the oil temp to fluctuate.
If you're really wanting to have a serious turkey meal, consider Bleu Cheese Dressing, Oyster Dressing, grilled bacon-wrapped asparagus, and pecan and goat cheese over greens. It's a Texas thing.
Enjoy it. This year, we'll probably do another 16# turkey - although I'm considering frying 2 ducks - my wife is suspect because of the fat content.
I made a circular shield of twelve inch sheet metal flashing. This protected the burner and lower portion of the pot from wind. It made a big difference in getting the oil temperature up and keeping it there.