Advice needed for Dinitrol on lower half of car

Hello everyone.

I took my car to a paint shop earlier today to get a quote on tidying up a few patches of rust on outer sill areas. The guy from the shop wasn't keen on attempting for various reasons so I said I would attempt it myself.

He recommended I spray along the lower half (just above the sill line) to match the black trim on lower bumpers. I am quite keen on that idea. I tried spraying a few times many many years ago with great results so am looking forward to tidying this car up.

I am stuck a bit though on what to use.  I am considering using Dinitrol 445 (in black).

My thoughts are as follows:

Sand down and treat rusted areas with Kurust.

Spray a couple coats of Dinitrol 445.

Primer?

Top coat?

Would 2-3 coats of the dinitrol do the trick? Could it look ok? Should I use a primer on top & if so what kind? Top coat I would like black, which kind?

Any help would be greatly appreciated.

Thank you