you can get huge areas from overpass.

Fetching data from a read-only mirror is a lot better than slowing down the editing API.

http://wiki.openstreetmap.org/wiki/Overpass_API

For the extract as PBF, what area is required? Only Thailand? How often does it need to be updated?

If it won’t eat up too many resources I can host it on my server…

Stephan