I got mine as a set, they are koni.
Not sure exactly what model etc they are.
One thing I will say tho is that the kit I bought from a guy who works for GSF (Did not buy them from GSF) was meant to lower my car by 40mm, I measured it against count vons car last weekend and newark and confirmed my suspicions that the car was actually lower, and it actually 2 inches lower so about 52-55mm.
Another thing to bear in mind is speed bumps and ramps on multi storey car parks, I have great fun with both.
Can post a picture of my car next to a standard ride height mk3 if you want?