ACRYLIC ENAMEL Vs. ACRYLIC URATHANE ?

If you want to match your old paint and have a good section(under trunk lid), to get a good sample, there is technology to get that very close. It is a spectrum analyzer(very pricey computerized gizmo) that takes a "picture" of your paint and matches it to current paint codes. I have used one from Martin-Senor(NAPA) and other major paint suppliers might have them.
Paint:
As far as painting the engine compartment and jambs, and anywhere else that you are not wet sanding and buffing, properly applied urethane is the ticket. Single step application and its shiny.
Safety:
Wear a protective mask! This stuff can kill you! Get one that has removable cartridges with a rubber face that covers your mouth and nose completley. About $30.00 worth of safety so you can enjoy your Mopar later.