I think clearcoat is the way to go for long-term shine. I've had good luck with wax but I would recommend an acrylic polymer rather than a wax. Stay away from ANY wax that has Carnuba in it. Carnuba wax is fantastic for show cars that are covered/garaged 90% of the time, but it has a tendency to yellow over it's VERY short lifespan.
On my 65 Mustang (and everything else) I use Meguiar's #20 Synthetic Polymer Sealant. It's a blend of more traditional waxes, acrylic polymers, very light buffing compounds, and fillers to help fill in small inconsistencies.
It goes on easy, wipes of easy and lasts quite a while. I don't know how long it will last on engine parts that heat up but I suspect it would last longer than traditional wax.
Great write-up! Unfortunately, I don't have any buffing wheels... I gotta do all mine with elbow grease, lots of cursing, and beer.