In a small bowl combine the brown sugar, salt, ¼ cup of the bourbon, the lemon zest, orange zest, and black pepper. Pour about one-quarter of the mixture into a 15-by-10-inch glass or ceramic baking dish. Place the salmon, skin side down, in the baking dish. Spread and pat the remaining brown sugar mixture over the salmon flesh, covering it entirely. Cover with plastic wrap and refrigerate for 12 to 14 hours.
Remove the salmon from the dish. Rinse the salmon under cold water to remove the brown sugar mixture. Pat dry with paper towels. Place the salmon on a large baking sheet. Brush the top of the salmon with 1 tablespoon of the oil and the remaining 1 tablespoon bourbon. Refrigerate the salmon, uncovered, until the surface looks lightly glazed, about 2 hours.
If using wood chips, soak in water for at least 30 minutes (no need to soak wood chunks).
Prepare the grill for indirect cooking over very low heat (200° to 250°F).
Meanwhile, in a small bowl whisk the vinaigrette ingredients. Slowly drizzle and whisk in the remaining ½ cup oil until it is emulsified. Set aside.
Brush the cooking grates clean. Add one wood chunk to the charcoal or drain and add one handful of the wood chips to the smoker box of a gas grill, following manufacturer’s instructions. Close the lid. When the wood begins to smoke, place the salmon fillet, skin side down, over indirect very low heat. Close the lid and cook until the salmon is firm, has a golden brown patina, and is opaque but just slightly pink all the way to the center, about 1 hour and 10 minutes at 250°F or about 1½ hours at 200°F. If you’re using a charcoal grill, replenish the charcoal as needed to maintain a steady temperature. Leave the lid off the grill for about 5 minutes to help the new briquettes light. Add one wood chunk to the charcoal every 30 minutes, or drain and add one handful of the remaining wood chips to the smoker box every 20 minutes before the old chips burn out. Remove the salmon from the grill and let rest for about 5 minutes. Serve the salmon warm with the vinaigrette.