I don't know of any turn key solutions, you will be better off simply adding another plug to your semi where your trailer cord can reach it ideally.  Then you will need to wire in a light converter in order to combine the stop function into the signal wires.  Get a good one that doesn't feedback into the system so you don't have to go add diodes to protect your taillights.  Heres a link to some.

http://www.towready.com/content/products.aspx?lvl=2&parentid=1500&catID=1535&part=0


Here are the truck side wiring diagrams for RV and SAE.