I ran Bilstein on my '86 GT with some aggressive lowering springs and really enjoyed them. I sincerely believe that the strut / shock valves should match the spring rates regardless of the manufacturer. If the Koni's are capable, for the price I'd have to try them out. You can always change them if you don't like the ride. Basically buying new springs and getting shocks + struts for free.
Seeing that this is a CR add, how many miles are on these parts?
I have never "made" anything, I just modify the things around me into useful items with abilities that were GIVEN to me.