ATHS has a few ads http://www.aths.org/cads.cfm?view=view&type=WOT

I have dealt with these people before
http://www.truckpaper.com/listingsdetail/detail.aspx?OHID=1911977
If you don't like the 7 speed, any Eaton/Fuller, Rockwell or Spicer transmission for a class 8 truck will fit.

Any of the older transmissions here will probably go for a couple of hundred. I will probably take a load of engines and transmissions to the Plunk's sale. http://berryhillauctioneers.com/auction.php?aid=531&page=inv

An individual who probably wants to recoup his money because it has been on the market a long time

http://www.truckpaper.com/listingsdetail/detail.aspx?OHID=2174844