Hi Rich.
We (me and Merlinman (Ian)) was looking at this some months ago. While Ian's was up in the air, Ian mentioned to me about bumpsteer. One thing I remember Ian saying about it was rosejoints should be used as well as some other things. I'll get in touch with Ian and add some comments.
Also found this article. Not sure if it's any use.
From here:
http://www.thedirtforum.com/bumpsteer.htm
In order to accomplish zero bump the tie rod must fall between an imaginary line that runs from the upper ball joint through the lower ball joint and an imaginary line that runs through the upper a-arm pivot and the lower control arm pivot. In addition, the centerline of the tie rod must intersect with the instant center created by the upper a-arm and the lower control arm (See diagram below).