I have a spear from a 15.5 gal sanke that I don't know what to do with. It would need to be cut down, but you could have it, just pay shipping.
You could also try looking at http://www.micromatic.com
. I've heard they sell keg parts, but I haven't really looked through myself to see for sure.
There is a picture with part numbers that I found on another forum: http://www.probrewer.com/vbulletin/s...ad.php?t=16436
Scroll down to the second-to-last post from a member named jrbeck.