I originally looked into electric steering for a tractor project as it can be easier to fabricate. My '40s flathead six Mopars could benefit too. The power steering for these L-head motors in the '50s had the pump mounted on the back of the generator. Fabricating a mount for a mechanical pump is okay too, but the electric pump is easier and looks stock.
There are several related technologies, with more methods being developed. The steer-by-wire can feel like a radio controlled robot, or it can have good tactile feedback. I only want to use the electric pump.
Some hot rod parts vendors supply kits for specific vehicles, but those are kind of spendy. I think the kits are based on OEM stuff that is similar to what you'd find in a salvage yard. There probably will eventually be a kit for an A-body. The integrated under dash unit is like having a set of gorilla arms that assists a manual steering system - there is nothing downstream where you would usually expect to see power steering components.
I'm mostly thinking of just using an electric pump for a tractor application, but here is the underdash integrated unit from a decade old Saturn
https://www.youtube.com/watch?v=BuShsA_cqNk