Honestly the only nerf that Zed actually deserves and needs, is a nerf to his waveclear (make his Q do reduced damage to minions, and make his E do reduced damage to them. Making his passive not work on minions, or also reducing its effect on minions would also be a good idea).
This idea that Zed pigeon holes you into building zhonya's first is just dumb.
Zed cannot 100-0 you from full HP at level 6, assuming you are both on equal footing of course. It just isn't going to happen. Zhonya's is an excellent item to counter Zed with, but that DOES NOT mean that you have to rush it every game versus him, in fact a seekers armguard generally works pretty well on its own.
Generally speaking when facing a Zed and I am not confident that I can outplay him, then I will rush a seekers, and then I will try to pick up an item that gives some HP (catalyst is a personal favorite here).
If I feel that I CAN outplay him, but I want to play a bit safely, then I will rush a rod of ages (for the extra HP and mana, and for the bit of sustain it provides), and after the rod is complete then I will go ahead and build the Zhonyas.
These are some simple examples, and I am aware that Rod isn't viable on some champs, but there are plenty of other options that you can choose from out there. You just have to be willing to experiment a bit.