Ive had 3 coilover sets on my valver and there was just one which would go as low as I wanted it to go.
Those are the GAZ coilovers which can go way too low. I removed the bumpstops once and put it so far down, that my wheels were rubbing everywhere even when going straight on a smooth road. The whole tyre fell into the arch on the front, which looked absolutely sweet, but it wasnt that fun to drive it.
The other coilovers I had were, H&R and Weitec.
The H&R set was pretty old and half worn, so I wasnt very pleased with it. The Weitec set on the other hand was a good set and its a KW product, but it just wouldnt go as low as I wanted it to.
If youre lokking for the best adjsutable set, get the GAZ set, because the rear shocks are also very good adjustable on their damping.