I went with Napa premium ball joints. They have a Kevlar insert that carries the vehicle. They have a breakdown of one at the store where I bought mine. It has grooves machined into the Kevlar to distribute the grease and once greased becomes extremely durable. Also comes with a lifetime warranty.

They guys that work at the store said they haven't seen any of the premiums come back under warranty, but have seen the standard ones come back.