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?

[old Rusty C10]

for the firewall I used engine paint on the last truck.. also you need paint on the floorboards as opposed to primer before you put the rust proofing down for it to stick right permatex makes that