Thought I had a better picture, but here's my interior shelf/bunk. I built it this way for my (ex)girlfriend's son. The 2 rails are removable - they just lift out of place. There was a foam pad that was on the shelf when he slept up there. Now that the gf and her son are no longer in the picture, its a great place to put dufflebags and clothes. The end supports are just pieces of inside corner trim mitered to form a cup. The shelf itself is 3/4" plywood, which has a 1x2 running from side to side across the 5' wide cabin for support. It easily holds 150+lbs.
The lack of cabinets is a lot more versatile, allows for more gear/clothes, and also gives the cabin a more open feel. I'll never have interior cabinets in any teardrop I build. They look nice and pretty, but I feel they add weight and take up space. Just my opinion though.
