I admit those look good.
On the shortie question:
Short primary pipes favor higher rpm operation.
The collectors are very short too.
That does the same, favors high rpm.
Now if you were dealing with a small engine, like a 302, I would be the first to argue for long tubes...
But with a 460+ engine, you aren't going to miss any low end grunt lost.
Same with a single plane intake.
As a matter of fact, big cube guys often like to tweak parts like these to soften the stump pullin grunt that keeps them from getting traction, breaks driveline parts, and twists bodies.
Just a thought.
You still got 3 options...
So which is it?