Some folks have the twin beds and aspire to have the setup that you have.
I would look into a trade with someone who has twins.
The swapout is very easy. The only difficult thing that I have found about retrofitting Airstreams is those darned Tambour doors. It is a trick to get the tambour back into the scroll ends.
Lots of patience required.
All you need for retrofit is philips screwdriver, drill with small drill bit, and rivet tool.
Bunks are great for kids.
Go for it!