If you are referring to 12 Volt surge protectors, I built my own. Consists of an 18 volt varistor in parallel with a 18 volt surge protector diode installed in a small die cast
aluminum box. Total cost probably less than $10 US ea. Installed half a dozen at various locations around the yacht's 12 V system.
Built some multi channel units to cover the masthead light
wiring and the
wind sensor.
For a direct shot not sure anything will make much difference, but over the years have replaced a lot of electrical/
electronics equipment damaged from inductive coupling of nearby strikes.
For the
shore power connection you could just pick one of the whole house protectors offered by most of the
electrical equipment suppliers (Siemens, Square D, Cutler Hammer e ct.)
Frankly