For 2000+ 4x4's
Quad4X4 told me they buy the balljoints from the same supplier as DC, this would not be my first choice.
Ingall's told me they don't sell lower balljoints.
Moog should have both upper and lower balljoints for 2000+ trucks on the market now. I called about two weeks ago and they had released either the upper or the lower, I can't remember which.
My lowers are wasted at 80K, about 1/4" of movement vertically.