Firewall/Interior Paints

[GMC Guy]

before i swap my 74 cab onto my 79 chassis, i want to paint the firewall and interior myself. for the fire wall i want a high gloss black finish, and for the interior i'm looking at silver (which is only going to be on the dash since everything else will be covered up.)
Also, i want to put truck bed coating underneath the cab and then on the floor to deaden sound vibrations and prevent rust.
i plan to prime everything first, but i need to know what primer/paint/clear combination will look the best and last the longest.
oh ya and i plan to use rattle cans, i sorta have fine wine taste on a cheap beer budget haha

the rest of the cab will be primered first as well, as will the rest of the truck until i save enough pennies for a paint job. so what primer/sealer is the best for external use?