Steering normally comes as a kit with everything you need so no real drama's there.
Electrics for the engine (fingers crossed) would normally consist of a control box, battery earth and live and depending on the size of the engine a tilt and tacho gauge. None of it rocket science.
If you start adding nav lights, stereo etc, you will have to do a bit of 12v wiring and add a fusebox. Pretty straight forward.
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