Alright great thoughts here. The strength of balljoints is not a concern to me, the advantage I saw about kingpin was the better steering options only. But thank you guys for the above suggestions, I will definitely be checking those out. That may swing my vote towards a Superduty axle.
As for unit bearings, they are not horrible, but in my experience they just don't hold up like the old stuff. I probably put 4-5 "high quality" ones on my XJ with stock tires in the 150,000 miles I drove it.