As far as I know, most of Renegade's stuff is OEMed. The side shift mechanism is made by Bobby Hart at California Motorsports. The shifter is the same one several people, including Patrick Motorsports, sell. I can't remember who it is that actually makes it, but Roger Brown at Power Haus II can tell you and he is designing a new mid engine shifter setup. I can't tell you if or how much of the adapter you are looking at is from Kennedy (KEP), but I know for a fact that they resell KEP stuff.
Unless you have a personal reason for not using KEP, I don't see a reason not to use them. I and everyone on this forum who has used their stuff has been happy with it. A few people have complained about their responsiveness, but I think that is because they are still a family business and do a LOT of work. I can't say enough about how impressed I was with their adapter and, especially, the fly wheels I have purchased from them. Also, when I got the internally balanced flywheel from them, they quoted me a price a little higher than the 28oz or 50oz part that normally comes in their kits, but when it arrived, the invoice price was actually cheaper!
Regards,
Lynn