This caught my eye. I'm totally ignorant of what an "ACOS" is. Can you enlighten?
Assuming that we're talking about some sort of coil-over type unit, coils should be fairly easy to find.
Eibach has an excellent page on one method of figuring out what the spring rate should be. http://eibach.com/cgi-bin/htmlos.exe...08459700020948
From looking at this page it appears that they offer spring ID's of either 2.5" or 3" for coil-over applications. http://eibach.com/cgi-bin/htmlos.exe...48628100020948
If this isn't a coil-over it may be that you can still use a coil-over spring. Just have to be careful about getting a spring with too tall of free length and buckling it under load.
I used to swerve around my hallucinations, now I drive right through them.