To adjust camber on the front you'll need to replace upper arms if you are going lower than OEM spec, regardless of what coilover you choose
I could be wrong though, but this is why I chose to go for mild drop on Tein springs to avoid other suspension mods, like front upper arms, rear camber arms and camber bolts
About the opinion on the D2's, it's one thing to read stuff on forums as opposed to actual experience.
I do believe that Docwra has had a variety of coilover setups in his time on his Zed, including the D2's.