I assume you intend to use a Mopar electronic ignition (or point dist) and a carb?

If so, many aftermarket wiring harnesses will work just fine. I would stay away from the cheapest harness you can find, but I think most between $120-$200 would work well. The really cheap ones are really cheap for a reason. You want a harness with different colored wires and are labeled every few inches. Pick one with some after purchase support. Rebel Wiring, American Wiring, and a few others have a tech line for if you have troubles.

The 86 steering column will work OK with the aftermarket harnesses. I don't bother with any one wire alt, too many have issues. Give me a standard wired alt please.

I don't know how far into your swap you are, but if you intend on using the 53s front fenders, a D150 chassis puts the firewall and front tires in just the wrong place, or the motor sits back inside the cab by 6" or more. A Dakota frame fits better. Been there, done that! Gene