Combine kosher salt, pepper, and paprika; coat pork roast evenly.

Prepare smoker with apple and hickory chips.

Smoke pork roast over low fire for about 8 hours.

Let cool slightly and shred the pork with forks.

Sauté onions in oil in a saucepan until translucent.

Stir in paprika, chili powder, red pepper, cumin, and cayenne; cook until fragrant (about 1 minute).

Add tomatoes, vinegar, ketchup, orange juice, brown sugar, mustard, salt, and black pepper.

Cook, stirring occasionally, until the mixture is thick and coats the back of a spoon.

Puree sauce and let cool.

Combine pork and sauce in a large saucepan; heat through, stirring over medium-low heat.

Pile sauced pork on buns and serve.