Perhaps  you can have them put adjustable legs on it so that when you don't need it, when you are back home, , you can extent the legs and drive out from under it , so that you can use your pickup truck normally. 

If doing so is an option in thailand.

Whatever you decide to get, don't cut corners on insulation...

That would be my priority. Once it's insulated well, you will minimize the AC usage...

There are stacks of helpful YouTube videos, from solar set ups to plumbing and flooring etc..

 

Good luck