I'm just guessing here, but since you've now internal balanced the 5.9, couldn't you now run a balancer/pulley combo from a later 5.2? The 5.2 is internally balanced, so would have a neutral balanced harmonic balancer. I believe magnums went to the balancer/pulley combo starting in '99. So maybe ask for a balancer for something like a '99 Ram with the 5.2.
This if course is me assuming that the 5.2 balancer will actually fit on the 5.9 crank. I figured it would, but don't hold me to it! Haha