In a large pot, cover the potatoes with cold salted water and bring to a boil over medium-high heat. Cook until the potatoes are tender, about 25-30 minutes. Drain the potatoes thoroughly and pour onto a baking sheet to allow to dry completely; refrigerate until well chilled. When they have chilled completely cut them into quarters.
Meanwhile, in a medium skillet, cook the bacon until crisp. Drain on paper towels and set aside.
In a large bowl, mix the mayonnaise, sour cream, barbecue sauce, mustard, and vinegar. Carefully fold the potatoes into the dressing.
Fold in the celery, bell pepper, jalapeno, red onion, cilantro and green onions to the potatoes and season with salt and pepper. Cover and chill overnight for best results. Garnish with additional sliced green onions.