Easiest fuel injection and overdrive swap would be from 90-93 pickup or ramcharger. Dakota can be used but needs transfer case or front axle swap.
Next easiest is 94-97 but need more electrical interface work and either transfer case or front axle swap.

In any of the above you lose full time 4wd transfer case. Up to you if you want to swap the front axle for something with locking hubs which will necessitate a matching rear axle...