Power option upgrades - Windows, Locks, Mirrors, Cruise Control

[InTitusville]

I have a 1994 Mazda B3000. It had a coolant in oil (milky oil) problem so I started doing work to correct the problem which I think was bad intake gaskets. As I did that I have the intake clean and bead blasted looking new. Noticed the power steering pump was leaking so bought a power steering pump. Figured since I have that much of it apart I would replace the steering gear box and noticed the steering column bearing was bad and found a nice column with tilt I plan to use. The truck doesn't currently have cruise control but the new column does and wanted to know if I can do it and what needs to be done to get the cruise option added since the new column has the option.

Also, I figured since I'm doing all these upgrades I wanted to take the basic doors and add power locks, windows and mirrors and wanted to know if the main wire harness has that or does the complete main harness need to be replaced. I have no problem changing the internal door hardware but need to know about the electrical system. I have a 1990 Mustang that doesn't have heated rear glass but the wiring is already there and just needs a switch on the instrument panel changed and plugged in to the existing wire harness and change the rear glass.