440 vs 360 barracuda

Your assumptions are correct. I may end up with a great 408 stroker. At the end of the day, the A-833 4-speed makes the car so enjoyable regardless of power. I have a set of 26 inch tall slicks that will work decent with the 3.55 gears. At the very least, for the 5.9, i would go with Edelbrock 58cc heads and a Howard cam, most likely: Lift .565 / .565, Duration @ .050 235 / 241.
A good plan indeed.
FWIW, (did you) check out the new Trick Flow head that is Magnum & LA capable? It will use LA intakes.
Rocker gear is supported via Harland Sharp and specific for the block used. AKA, pushrod or through head shaft oiling.