Hi shohola,
Welcome to the VCCA's website!
I don't know the answer to your questions, but I suspect that your proposed tranny swap is more complicated that just finding new parts and bolting them in.
Although this website is mostly about preservation and restoration, there is a forum for Personal Modifications further down the list. That's where you'll find folks that do these kind of swaps. Here is a link to that forum:
https://vccachat.org/ubbthreads.php/forums/86/1/personalized-modifications.htmlAnother place to look is the Tech Tips page of the Stovebolt website. Their site is mostly about modifying Chevy and GMC trucks. Here's a link to that page:
https://www.stovebolt.com/techtips/My suggestion is to gently suggest that your wife give the stick shift a try in an abandoned parking lot. Remind her that back in the day, these trucks didn't come with automatics so men and women learned to drive them and it was no big deal. I recently taught my son to drive a stick so he could drive my 1928 Canopy Express. He picked it up pretty easily.
If you keep your truck in its original configuration, you'll have a unique vehicle that people will appreciate for being a survivor and a representative of a bygone era.
Good luck either way! Dean