Are you asking about the adjustable rear strut that replaces the dog bone portion of the linkage? If so, Durablue makes one, here's the link: http://www.durablue.com/pandp.php?cat_name=Lowering%20Kits
Just scroll down and you'll see it, part # DAS-4H for '86 and DAS-7H for '87-'89.
Or if you're talking about different linkage setups, then there is the stock link, no-link, and CR500 link. The stock link is obvious, it's the stock linkage, shock, swingarm, and frame. The no-link doesn't use a linkage and requires an aftermarket frame, swingarm, and shock. The CR500 link requires an aftermarket frame, swingarm, shock, and linkage.
Most all aftermarket chassis companies offer all of these configurations, e.g. Laeger, Lonestar, Walsh, Roll Design, etc., etc.