Help - How should I paint this?

[SBC]

Hi all - I need a plan!

This is a case where I've read all the hype on how to fix a rust bucket, but now I got a pretty clean product and I'm not sure how best to proceed.

I'm replacing rear spirings, and at the same time attempting to cleanup my Nova's underside while its accessable.

I've got near-white blasted metal as you can see below, except for some residual pitting.

I bought some Rustoleum Pro 93% zinc primer spit-bombs but something tells me 'its not worthy'.
POR-15 is in route if needed.
But not over clean metal, right?

If an air- spray product is best, I've got a Devillbus spary-gun, but need to buy a cup.
And a typical 3.5 HP compressor.

I've got too much labor invested at this point not to do it right.

I need a plan! -
Thanks - Bert