I've been down this road. Mine were so bad the truck wouldn't stay in its own lane. I was pulled over because they thought I was drunk. I usually do all my own work but this needed special tools and one of the nuts needs around 600 ft-lbs of torgue I believe. I had mine done as Duff's Brake and Spring in Medford, MA which is just north of Boston. I bought the parts (thinking I'd do it myself) but they put them on for $40 more than what the tools would have cost me AND they aligned it. I dropped it off in the morning and picked it up at the end of the day. I have had zero trouble with them since.
Depending on the parts store, I've heard them called ball joints, king pins, and trunions. Good luck, let us know how you turn out and keep grease in them.