the power steering can be swapped but you need to also swap the column as they are different lengths
you should be able to buy a big block engine harness & move the wires around in the firewall plug on the new harness to match the wiring in you car , they all use the same firewall plugs
not sure what the difference is in the wiring harness , which harness are you asking about ? , the engine harness had a plug near the firewall so the engine could be installed wired & just plugged into the engine compartmment harness once installed