Zinc, Etch, or Acid Etch?

[StescoG66]

Straight and to the point - which is better to treat bare metal to hold at bay further future corrosion. Took rear light clusters out my resto project and rubbed back to metal - what to treat it with to cover the bare stuff over, but which is best? Zinc primer, Etch Primer, or Acid Etch.

Thanks for your help.

[226bhp]

Etch primer.