Matt- sounds like your front struts need to be replaced. The problem with going with Bilstein Heavy Duty's (HD's) for a firmer ride is that you don't know if you'd like the the stock/Bilstein "Comforts" setup when new.

If I were you I would do the following esp. since your wagon has 122K miles:

1) replace the nitrogen spheres; all links in the rear (make sure you get the updated ones); and replace the swaybar bushings;

2) replace the front struts with Bilstein Comforts and replace the swaybar bushings with the updated ones.

Once the whole suspension is rebuilt, you will like it.

:-) neil
1988 360TE AMG
1993 500E

PS: make sure you have the stock wagon springs