Find out that Sunry was having an affair, then mention it to him to get him to confess it, make sure YOU bring this up in the case and your opponent doesn't, or else you get quite a thrashing. Also find out from the guy who rents the room beside the dead Sith's that the Sith was a dark jedi. Those are some strong points. Don't mention that he was injured either, it doesn't help.
If you get him free like I did then all the items bought from Manaan are at a cheaper price, very much worth it for you "thrifty" people out there, although the most expensive thing I bought in the game were cards.
Not counting HK-47 of course