Studs? - Installing a Crib Side in a Bunk

My wife and I are the proud owners of a 172.  It is a perfect fit for us and our 2 year old son.  We are expecting twin boys any day now and I find myself thinking often how we are going to make the 172 work for the 5 of us.

I am no carpenter or engineer, but I can handle most do-it-yourself projects well, albeit slowly if I'm breaking new ground.  My question is around how to create a safe bunk bed out of my 172 for my twin boys.  I've been thinking of turning the top bunk on the front side into a makeshift crib (for the twins to share), borrowing our crib mattress from home.  I believe the internal framework consists of wood (correct me if I'm wrong please).  I was thinking of creating a locking wooden gate with crib rails to keep the babies safely in the bunk.  Does anyone have a diagram of how the rPod is constructed or some advice on fastening onto the framework?  Will a household stud detector work in the rPod?  By doing this, will I be ruining my perfectly good 2009 rPod 172?

I really like this trailer and it's completely paid off, so while I have thought of upgrading, I would be much happier making our current TT work.  In addition to crib space, I want to put up some additional shelving/storage - any ideas around built-in stuff will work (we've been using hanging fabric shelves attached to tension bars, but I don't think they'll be safe with three little boys.

The studs in the walls are aluminum (actually, each wall is a one-piece frame) filled with styrofoam insulation filling the void.  The studs in the ceiling are wood, again with styrofoam insulation.

Check this out

I'd be interested in that. That's a generous offer.

Markthesharks mod looks awesome.  To bad he hasn't posted since July - I doubt I will be able to get the blueprints.

GaRedneck81 - thank you for the generous offer.  That FLIR camera sounds very cool - I never thought of using that.  Unfortunately - it's sort of the cart before the horse.  I have to get the rPod livable before we can take the family out on a trip.  I'm going to take my stud finder out there as soon as temperatures get above freezing.