I did a combo of 3 and 5.
I got a used psc box for a 98-2002 for cheap, then I modified the frame to take the box. It’s not too hard of a job if you can weld… Or have a friend who can. You only need to relocate one bolt hole. I picked up a lower shaft from a part out and didn’t have to modify mine. One part not on your list is the hydraulic hoses, they arn’t the same so you need those to.
As to blocking off the ports, they ship blocked off so no worries there.