All of the moving components of an inboard steering system is either inside the boat or the rudder which outside and under the boat. I have not seen or heard of any for a kicker to inboard steering rod assembley. Have you looked into trolling bags? They could be a possible solution to your problem.

I don't know if it would work but you could mount the kicker directly on the center line of the transom behind the rudder and you could the possibly steer with your boat with your steering wheel using the rudder to guide the boat.