I have the UPR adjustable panhard bar with the rod end bushings. I went with them because I also have their rod end LCAs and I've been pretty impressed with them. Any of the brands mentioned in this thread are a sure shot, but my vote goes to UPR.

 

Just intalled the J&M aluminum adjustable panhard bar last week. Its on sale at Americanmuscle.com
http://www.americanmuscle.com/jm-panhard-0509.html
quality piece, easy to install, lightweight.

 

I have the J&M aluminum panhard, found one "open box" for a good price...but, I agree with the others about that style being a pain to adjust. I haven't done anything with mine, but the passenger side jam nut is up in the panhard bracket where it's basically impossible to get a wrench on.

 

I agree that it was difficult. I followed the directions given in the write up on American Muscles site. In that write up they suggested wedging a screwdriver against the jam nut. I found it easier to do the following:

After centering the axle, I tightened the jam nut as tight as I could get it by finger, then placed a set of needle nose vise grips on the jam nut to lock it in place (dont know what else to call them but they are vise grips with a long nose rather than the short rounded nose). I used this vise grip to get a few more 1/4 turns on the jamb nut then left it clamped in place. The jam nut and provided a wedge in the bracket so that I could tighten the entire assembly from the drivers side.Once it was locked in, I tightened the jam nut on the drivers side and was done. Worked great.