55.2-59 help/advice on planning please 1957 truck build swap

[Missyblue]

I need advice and expertise my mechanic is good for helping swap but not so familiar with options for these old trucks. I have been scouring threads and places but hard to find direct advice. any you have is greatly appreciated. so for the big stuff I'm currently figuring out

I have a 1957 gmc stepside my family is giving me a 1990 chevy van with a rebuilt 350 tb engine and I have a 700r4 transmission. planning most likely a mustang ii based off previous advice so I have disk brakes and can utilize power steering

1. what else could I use from the van as far as accessories? could I utilize the power steering or any of those elements? just trying to see how much I could get out of the van that is usable.

2. what steering column options do I have new/old where I could utilize my original steering wheel and I want automatic and don't know if I care. kinda like key in dash but could go either way. I have heard ididit is highly recommended for quality but pricey. curious of other new or old options you have experience with

those are the big ones currently just trying to learn. much appreciated.