TT,
I presume yours is a 2 wire alternator, like mine?
Anyway you're looking at wire that will carry a minimum of 30 amps + bullet connectors to suit. I tapped-up an electrical guy I know, who came & did it for me - job done in less than 45 mins.
Also look at this article from Shazaam!
http://217.199.188.40/xmb/viewthread.php?tid=2042 Good luck!