You would be working with the EV-200 but with Twin Verados, you would need to hydraulic autopilot system. T70157, then with Verados, you would need the Verado hose kit as well, A18127.
The EV-100 does not have the capacity to work with Verados, the option above is the only option that will work with your vessel.
The EV-1 will not work as a heading sensor only.
I would suggest the Airmar 2183 heading sensor (T70132) for heading data for overlay capabilities.