For my money, I would rebuild the king-pins and replace all the suspension bushes. Adjust the steering box a little if you have room to do so but as another poster stated, it is easy to screw it up by over-adjusting it (also a little scary on that first test drive when the steering won't turn past center and you can't avoid your neighbor's nice new cadillac. Not that I would have any experience or anything ;)
I am surprised at the post saying that the semi-shimmies were solved by a sway bar. As Spock would say "Illogical." Not to put him down but I suspect he tightened up some other things along the way (like, reduced some play in the front end with the brackets/links).
I drove a VW Westy for a loooong time. When the speed limit was still 55 I would snuggle up behing them and let them "tow" me along. Of course the buffeting was very tiresome and on occasion the trucker didn't want to play and would do things like sway around, brake or go 75 (hah, in MY VW???). In that instance, the buffeting was very bad and we went though steering bushes and ball joints like candy... saw a set and they were SCARY.
What's the point? Oh, yeah, see to the suspension bits first and I betcha the handling will improve dramatically.
Save the sway bar for when you want to canyon carve.

Mike!