I thought someone has posted the trailers from the original Thai website before, but for some reason it has either disappeared or my mind's playing trick with me.

Anyway, slightly better quality 'domesticised*' trailer (teaser) from iFilm:

And Full-length domestic trailer: http://download.ifilm.com/qt/portal/2658636_200.mov

*It's exactly as the official teaser #1, only with English title cards.

And the trailers from official site:
Teaser 1: http://www.beautifulboxer.com/flash/preview/teaser.mov
Teaser 2: http://www.beautifulboxer.com/flash/...trailer_hi.mov
Trailer 1: http://www.beautifulboxer.com/flash/...railer1_hi.mov
Trailer 2: http://www.beautifulboxer.com/flash/preview/trailer.mov

Official site: http://www.beautifulboxer.com