You DO NOT need shackles on both ends of the spring - just on one end. Most guys on this forum are too young to remember when hot rodders ran "dead perches" instead of panhard rods. A dead perch is simply a solid shackle that doesn't move - all the spring elongation is taken up at the opposite...
I am impressed with what grace you are able to take "constructive criticism" from these guys.
Just don't let them dictate your build to the point where it has none of your unique character.
"Build by committee" is a sure way to a plain, ugly car.