For your application? I dunno - BUT - zinc coatings would dissolve in a matter of weeks in my world - in fact, we used Zinc as a sacrificial anode so that would "go off" instead of everything else. As far as stainless goes, we used 816, and 816 ONLY. Even that would corrode unless it was passivated and polished.
The problem that we encountered with zinc was structural fasteners failing due to hydrogen embrittlement.
We had used cadmium plating prior to the zinc but regulations made it near impossible to use.
Then we found PTFE coatings which met the offshore needs without sacrificing the strength.