Bilsteins can be rebuilt with custom valving for ~$65 each, plus
shipping to California.  Check the Bilstein website.  This takes a few
weeks but for a few bucks less than the Konis you can get a shock with
exactly the performance you want.

I have been told Konis are somewhat softer than Bilsteins at the base
setting but the rebound adjusts quickly to a quite stiff setting.

There are two versions of Bilsteins for Vanagons:  heavy duty and
touring.  The heavy duty version offers the best control.

Ed