If I were starting from scratch, and faced with building a sweet stroker SB compared to (the lesser performing Big Block) 383, my biggest concern would be making everything work together, and work right, to produce a nicely performing car.
Going factory (or slightly better than factory) has paid off for me numerous times in the past to avoid some pitfalls of going completely aftermarket. Going factory is simpler. I might choose your 383, when I want the path clear on what to buy, what to do, and ease of bolting stuff together with a nice outcome. But the BB is heavier, no doubt about it.
But a lighter SB crate motor, ready to drop in, that should already be balanced and tuned for performance, well heck, this almost seems a no-brainer. I would go with your crate motor, unless you're dead-set on dropping it into the Duster, which would also be a pretty sweet ride, mechanically, power and weight-wise, etc.
I may be a bit obsessive, but some of my projects require more research to figure out what I need to do to produce the results I want, than the time to execute and do the work to make it happen. Maybe I'm aging, but I get a bit weary of "research time" exceeding "doing time."
If you're looking to save $$$ or time, that crate motor you describe would function well in either the A or E body.
But with more work and research, the 383 stroked out with some $$$ may outperform or match the crate motor. But it will still be heavier.