GenIII A518 Question

I am confused on something and hopefully you all can help. I have seen it listed that I will need and that I wont need a spacer.
A couple sites show using the adapter and spacer when bolting a 518 to the back of a Hemi like the one listed first in my pictures.
Then some say I only need to run the flywheel adapter like pictured in the 2nd picture.
I am hoping someone can shed some light on this for me.
And I should be able to used any shifter that will allow for 4 speed detents if I run a manual valve body? right?
Thanks for help.

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A500 and A518 are 3 speeds the OD and LU are controlled by pressure and solenoids. I'd recommend a hgm controller. Any old shifter will work.