For the pork and marinade: In a bowl, mix together the paprika, brown sugar, salt, pepper, mustard and cayenne.
Put the pork in a resealable plastic bag, add half of the dry marinade, seal the bag and rub the marinade into the meat. Refrigerate overnight up to 24 hours.
Preheat the oven to 270 degrees F.
Remove the pork from the fridge and rub with the remaining marinade. Wrap in aluminum foil and put on a baking sheet. Bake until tender, 7 to 8 hours. Pull the pork out of the oven and shred it with two forks
For the vinegar sauce: In a mixing bowl, whisk together the ketchup, vinegar, maple syrup, pineapple, cayenne, mustard and salt.
To make the sandwiches: Put a portion of pulled pork in a bowl; add a few tablespoons of vinegar sauce and mix. Pile on the toasted brioche buns and serve with a side of plantain chips.