That is Bils std valving for coil springs. Normally when you hear of a ride quality complaint it is the rebound valving. That is contrary to intuition, but it is usually the correct conclusion. The rebuild guide (
http://www.bilstein.com/7100_Rebuild.pdf) shows a 345 rebound stack. Might be worth trying a set of those. The next step down is 275, which is quite a change. Unless the ride is horrific I would not go to those as the first step.
It is messy, but fairly easy to do this work yourself. The only special tool needed is their disassembly tool, which is not a lot of money. Can have some 4X and most motorcycle shops do the N2 charge.
There is no reason that you have to stay with their off the shelf valve stacks, but unless you are familiar with doing this sort of thing it is very easy to get lost.