Place potatoes into a large pot and cover with water; bring to a boil. Reduce heat to medium-low and simmer until pierced easily with a fork, about 10 minutes. Drain and cool.

Place the bacon in a large, deep skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain and transfer bacon to a paper towel-lined plate to cool.

Stir white vinegar, cider vinegar, sugar, salt, and black pepper together in the same skillet; bring to a boil and remove from heat to cool completely. Whisk sour cream and mayonnaise into cooled vinegar mixture until dressing is thick and creamy.

Mix potatoes, dressing, onion, parsley, and chives together in a bowl. Cover the bowl with plastic wrap and refrigerate until chilled, at least 2 hours. Stir bacon into potato salad just before serving.