My mistake. I looked all over the website, but couldn't find that info on the undecorated RTR car. Maybe they will come out with a version of each. Other options include dome heights and fittings, Cardwell draft springs, handbrakes- you get the picture.
it doesn’t show or say if it has K or AB brakes… so your suggestion, while useful for the decorated models, is not so useful to actually answer the question that has been asked ;) (We’ll assume that the kit allows both)