Hello airstreamers!

I am very much in need of assistance. After purchasing a 2009 30' Classic, we find ourselves in need of more sleeping space. We have four small girls -ages 6,5,3 & 2 and are expecting another little one January 1st. (-We will have a
louder airstream than most!) With this in mind, we plan on packing them in like sardines. Currently we have plain twins and they sleep toe to toe- which is fine for now.
After reviewing some threads about bunks and realizing this is probably a better idea with an older airstream due to sturdier construction, I am wondering if something like small travel hammocks may be a good idea. This would allow us to keep all of our much needed under-bed storage and closets as well. Hammocks are probably fine for the older girls and we would put the little ones in the beds.
Any thoughts on this? I am wondering where I would place the mounts for one hammock on each side of the rear. Cabinetry perhaps? I have no knowledge whatsoever regarding the framing and how to mount things to the walls. Any advice would be most appreciated.
Thank you,
Thorny