I think a lot of it comes down to what you are using it for... and what comforts you are willing to give up.
A teardrop is a way of going camping, without having to sleep on the ground. The fact that it's got air conditioning or heat is a bonus you don't usually get in a tent, in a sleeping bag.
Oh, the galley is a bonus too. You no longer have to store your stuff in the trunk of the car, and cook on a picnic table.
Hurricane evacuation, or extended camping is an entirely different animal.
There you might want more comforts, like a porta potti for example. or even a shower. A hurricane evacuation trailer would probably have interior seating, and interior cooking. Remember, we're not camping any more, but living on the road.
You can always drag your stove out and put it on the picnic table, but if the weather is bad, or cold, or wet, you'll want to be inside.
For a hurricane evacuation trailer I would suggest at bare minimum, a T@B with a porta potti. Many of the older tiny travel trailers would work too, like the Serro Scotty's or the smaller Shasta's. If you wanted to build something I would suggest a T@B clone, or a Puffin, or even a winter warrior if you want a lower profile on the road. If you really want to get daring, build a T@B XL, the one with the bathroom in the middle. And if you do, be sure to take lots of pictures.
Mike...
The quality is remembered long after the price is forgotten, so build your teardrop with the best materials...