Either route will be fine...Epoxy primer etches but also has some build to it (so it can be blocked)Also it is not porous where it will absorb moisture
Etching primer has no build to it but etches to bare metal very well. It IS porous.
They both can be followed up with a 2k primer.
With bare metal I prefer to etch, then epoxy then 2k primer. This will yield very good adhesion and plenty of build for prep.
