I know that Audio from the Game that Darth Ender supplied you with...
lol a lot of it is no good... But it is james earl jones and it almost sounds identical to vader...
The use of lines is good.... There is a bit too much high and high mid frequencies in the Vader voice though and in general... What are you using to do the edit with?
I cleaned it up a bit but I suggest you clean up each sound element individually and then mix them together it's way too toppy overall while the music sounds fine
http://www.mediafire.com/download/7nd47pp102c6qrh/vader_conversation.wav