I've had issues on staring similar to yours but I think it is ignition box and or grounding issues, not low amperage from the batteries
I'm going to do some rewiring this winter along with taking another MSD7AL2 box and a MSD digital non programmable box and another MSD transformer coil and two of the early red coils for the 7AL2 race boxes and see if I can figure out exactly where my car starting problems are
I'll post the results and my thought on what caused what when I'm done