I'm going to use Krylon "Rust Tough" in matte black. I've tried used a flat black and then spraying a gloss clear over it. You end up with more of a matte finish but the Rust Tough matte black looks a lot nicer.
Some people like having those components powder coated since that stuff dries hard. Eastwood sells a powdercoating kit for the DIY'er.
I've been using POR-15 for larger components. That product also dries hard. You have to topcoat the POR though since it is not UV safe.
On a side note...if you are planning on simulating the cosmoline coating on the LCA's try spraying them with Seymore's Stainless Steel paint first and then spray them with Krylon Battery Protector. It dries hard like a paint and looks very close to cosmoline.