Both are films that fans of Ong-Bak will want to check out. The Bodyguard, primarily a starring/directing vehicle for Petchtai Wongkamklao, or Mum Jokmok (or Dirty Balls, if you insist!), features Tony Jaa in a small but high-profile role.
Born to Fight is a gritty actioner directed by Ong-Bak choreographer Panna Rittikrai.
Neither have been available on legal DVD with English subs.
Here's the story on The Bodyguard, not that it really matters:
Chaichol is both devastated and furious when his father, Chot -- the richest man in Thailand -- is assassinated. He fires Wongkom, his late father's bodyguard, for failing to do his job and the situation worsens when Chaichol finds out that he himself is now a taregt for snipers. It doesn't take him long to realize that the only person who can save his life is Wongkom, the devoted bodyguard he recently tossed aside.
(Cross-published at Rotten Tomatoes)