Do you know which benefits/defects you have changing just the suspensions leaving the original springs ? is it a reasonable setting or you have to change them both?
i'd go for bilstein
cico

 

Hi there.
I would reccomend a complete kit ...reason being a matched kit is tested and designed for the car (especially when its a subaru).
It is more expensive getting a kit but I would say better in the long run ( springs not up to the job ..labour costs of fitting just shocks).I was going to just get Eibach springs but went for the Prodrive kit ..a lot of money but worth it its a new car!!
Really depends on what you want from your car and how you use it.
I don't think you can get Bilstiens aftermarket anyway - Prodrive have the tie-up!!!.
Hope this is a help to you ..post how you get on!!