@Vee274 From the pictures and description of the second bedroom, it is small, with the double bed pushed up against the wall. A single over double bunk bed would block the window and probably make the room seem smaller, unless you are catering to couples with children. Who is your ideal guest?
I have also had people request 5 for my small 2 bedroom cabin. I would never put in an over under as I prefer to attract 2 couples, and bunk beds are (IMO) a nightmare to make up with linens. I won't even go to a sleeper sofa as the cabin is ideal for 4 and crowded for 5+.