Deka vs. Interstate AGM for chassis?

I bought a 2003 Dodge 2500 with a Cummins and 6 spd, at the end of February. It was built on 6Jan03 and had the original Damiler Chrysler batteries in it, two "green eye" (Delco/Delphi) batteries with the Damiler Chrysler labels on them. They were sluggish but started the diesel. First thing I did was shop around for the cheapest deal on AGM batteries, two group 65's. The only sale I found was Pep Boys, Bosch, 25% off, so they were $150 rather than $200 like everyone else. I just looked, the 25% off offer at Pep Boys is still going, until May 31 and does still include batteries. It says online purchases, but I just went in the store, actually a Pep Boys shop not attached to a store, and they honored the price, ordered in the batteries and I picked them up the next day and left my old batteries.

https://www.pepboys.com/product/details/838869/01660/2003/DODGE/RAM%25202500%2520PICKUP/0/6-360%2520%25205.9L%2520Dsl?quantity=1

Charles