While most private-jet manufacturers boast about their wide range of choices for interiors, Airbus is offering a simpler option for busy buyers: off-the-shelf interior designs. Introduced in April, the new Airbus ACJ319 Elegance model features a nearly 79-foot-long cabin that is fitted with two bathrooms and a galley at the front and a bedroom with a private bathroom at the rear. In between, the cabin is divided into three areas that owners can fill with a range of predesigned modules for conducting business, …