I'm a sucker for tragic endings so I'm going to offer a third option: The protagonist dies during his showdown with the kingpin, but in a final monologue, confesses his love to the heroine, while telling her she needs to let him go down as the crooked, murdering bastard, dope fiend that he is in order to save her own career and rid her of any allegations of being an accomplice. He doesn't care that everyone knows the secrets of his second life, as long as she knows his side to it. He makes her promise to him that she'll do this for him.
The premise of the story sounds really interesting. I imagine if you began the story just before his coke addiction gets out of hand, or just after (allowing for some flashbacks), you could make a really long and deep movie of it.
Other than that, the hobo ending and the drug-induced hallucination of the happy ending sound like good mind-fuckery.