I went on the Raymarine tech support and asked the following. I will post what they respond with. Also here are some pictures of what I have.
"My S1 Wheel Pilot is good and I have it integrated with my Axiom+ as well as the depth, speed and wind instruments as well as a Fusion Radio (that integration is phenomenal) and a Standard Horizon 2410 with AIS.
The S1 has been a champ and I got you all to rebuild it a few years ago, but I am sailing in rougher water and would like to go more robust. Can I simply swap the wheel drive with a motor connected to my Rudder quadrant. I am assuming I would need to run separate power to the motor and then use the + and - on the computer controller to provide the controls?"
You can integrate an AP control head (70) via STNG to ST1 as I did it for a friend. But, my current set up is so solid I do not want to change much. My big issue is last night crossing the Chesapeak Bay the wheel drive struggled to handle the waves, and when I was dealing with the one thunderstorm that rolled over me at the mouth of the Potomac with 46 knot winds

fuggedaboutit.