Ardupilot Sailboat. Component Selection

I would like to build an autopilot system similair to the Raymarine ev100. to install on a Macgregor 26X. The linear actuator used to control the tiller is easy to source. This one seems very suitable. The interface between the linear actuator and the Pixhawk that I intend to use is this one.
Being very new to this Pixhawk system I am not sure what the best way to incorporate the “head” for programming and display so I’m asking for anyones guidance on how to interface with the Pixhawk when there is no RC required. Can mission planner be connected through serial permanently and run from a tablet or should a custom interface be used.
The raymarine unit uses this ‘head’ but has limited features.

I welcome any and all replies.