<<<If you cant find a stiffer bar>>>

Per,

I did find a stiffer sway bar:

http://www.p-s-t.com/swaytv.html#VOLKSWAGON

You can get performance bushings OR standard Bushings
$159 Kit
$119 Kit

Vanagon     Front   Rear

1980-86      1       7/8
1987-93      1       7/8

The stock front is 7/8. You can increase front to 1"

If you add a rear  bar you must increase the front to be balanced.

Robert