Questions on a Swap Before Any Serious Considerations

It is very feasible and you are right the rear would have to go a 8.25 is a great candidate for it and pretty low cost also. There are a ton of build threads here on doing exactly what you want hust look around in the small block section.
Right, right. I figured it shouldn't be TOO difficult considering the Duster exists with those options, but I wanted to be sure.