Need transmission help 2000 Rodeo AT 4WD

Two experts I trust tell me the sprague in the transmission is weak or worn to the point that a rebuild or replacement is in order.

Can anyone suggest a rebuilder, or where parts could be had for my guy to do the rebuild? I'd go used, if it made sense. I'm near Cincinnati, FWIW.

For used, here are a couple of sites I've found that you might be able to find a good salvaged unit:

http://car-part.com/
http://usedautoparts.everdrive.com/
http://www.partshotlines.com/
http://www.woodfins.com/