If you want to do this mod by yourself, I think it's a good place to get started :) I can't give you precise information as of now because I don't have the game with me but you can see where the dialogue branch leads if you use tk102's dlgeditor:
http://www.starwarsknights.com/tools.php)
Go to the view menu and select the option that says something like "show indices".
To give your pc a lightsaber, crystal or other item, you will have to use a script like this one:
void main()
{
CreateItemOnObject( "item_template", GetFirstPC());
}
Replace item_template by the name of the item's .uti file.
To attach the script to the dlg file, simply select the dialogue branch where you want to fire the script from and type the name of your .ncs file (without the extension) in the field called "script".
Since this is no longer a simple modding request, I am moving hte topic to the general HL forums.