What material for Risers?

[fishmore2013]

Can anyone comment on the set up and placement of weight in these boats?
Old set up
2 main batteries all the way aft behind and up against the gas tank(plastic), 3 car batteries for the trolling motor located all the way in the forward compartment.
Potential new set up-
3 trolling motor batteries located at same level as the gas tank(below floor) under the front of the Centerconsole and then the 2 main batteries on the deck under the centerconsole.
I would think the more weight located lower in the hull would be better?
The pic is of the old Battrey compartment located in the area about two feet infront of the transom below the floor.
Thanks Jon