We have three kids and a triple bunk setup and we're only going to keep it a few more years. The bottom bunk is tight and okay for a younger kid but a bit claustrophobic, and storage is a challenge. We bought it used for cash and knew it wasn't ideal but also knew we'd upgrade in a few years when we figured out what we wanted in the long run. We want a fifth wheel again for sure, and will either get a standard trailer with a separate bunk room or a toy hauler with drop down bunks.
With an F150 your options will be more limited. My sister has a lightweight TT with a rear queen slide and a quad bunk room in the front - you might look into that sort of setup. Truthfully there aren't going to be many trailers with a separate bunk room that you can pull comfortably with a half ton.