That's wonderful!
I've heard this is a good one.
http://www.knitpicks.com/cfaccessori...y.cfm?ID=80583
I always wind my own, but it would be hard with a lot of yarn. If all else fails I use this method and I make them in nice cakes like the ball winders do.
Bottom of the page- how to wind a center pull ball
http://www.knittinghelp.com/videos/knitting-tips