Well, I'm a loyal Thor Industries RVer, and partial to Dutchmen and Keystone. So, I'm pretty familiar with the Keystone brand. I just went through every floor plan on Keystone's line up and couldn't find a rear living with bunks in a travel trailer format. Now, if you go 5er, there are more options.
One other thing you might consider, a Toy Hauler! They make some pretty nice bumper pull Toy Haulers with the bunk beds (Queen size or bigger) in the back that slide up and down. Open that gigantic tail gate and you've got one dandy view. Drop that tail gate down and turn it into a porch! There's a new possibility. But, in the winter, if you get snow, it might not be so pleasant opening that big door for a great view, unless you wear a red suit and your coach is pulled by reindeer! Still, it's something else to think about!
Sorry, I still have had no luck finding a rear living travel trailer with bunks yet on the internet.
