Get the bunkhouse with a door to a room for the kids.
The bunkhouse is worth it's weight in gold.
Your youngest can be napping or sleeping for the night and you still have full complete use of your travel trailer. You can cook, use the bathroom, play a board game with friends while it's raining outside; and the littlest one is deep in slumber.
Our first camper had separate bunks but they were not in a separate bunkroom, the bunks were part of the main camper area with just a curtain closing for privacy. If someone was napping, you couldn't go into the camper period without that person waking.
Now that my kids are older and not napping during the day, it's wonderful that they can shut their bunkroom door and still get away from the adults. My youngest is only 8 and goes to sleep earlier than anyone else. I can't tell you how many nights she has slept in that bunkhouse at 10pm and her parents and brothers are up til midnight watching a movie and eating popcorn while it's raining....and we're not disturbing her sleep so she wakes up happy and rested the next morning. Nothing worse than trying to go for a hike with a kid that had her sleep disturbed all night long the previous evening.