There are a few ways to go. If the ren units are close to an express, you could use an LE/RX unit in the express and then cable from the Express to the Renard units. If not, then I would use Kit 1 because then all you need to do is make an adapter cable to connect between the Lynx unit and the Renard. Attempting to use Kit 4 on the Renard would require you to make mods to the Renard units which is obviously much more difficult and for many not worth the cost savings. Of course, remember that the Renard units need to be configured to run on DMX to use them with RJ's equipment.