General Paint questions for a black 94

My Z-28 was recently involved in a little fender bender, I won't bore with the details.
Hood, fender and bumper cover are done.
I'm ordering new panels next week. Going with a harwood fiberglass hood.
My questions for you good folks are:
Do I need an additive for the paint going on the urethane bumper cover? I would assume if I do that applies to the primer as well. If I do need one, what is it?
I'm wanting to fill the emblem hole on the nose, any idea what the best filler would be for urethane?
Same question for the rear sail panel, going to fill the 'Camaro' lettering and re-shoot it.

Can anyone tell me what brand of paint we should be using, someone that carries a color that will match pretty close to GM black.

This is the first go I'm going to have at painting, but I've got experienced help, I just don't want to go into this blind or make a bad assumption.

Thanks!

For the urethane bumper you're going to need an adhesion promoter that'll go on before the primer, then use whatever primer you want.

For filling the front nose I'd use a plastic welder, since the area is small enough, and for the back I would either use fiberglass or plastic filler(bondo).

And lastly, for paint I'd use PPG or DuPont...that word looks weirder and weirder everytime I see it.

Thanks for the info!