The topic that won't die!
I'm not saying it's not important; it is! But there is so much diverse opinion on what oil brand has the "proper" levels of zinc, and what doesn't. And, believe it or not, whether it even matters as much as everyone is saying that it does.
For me, since my car doesn't get driven that much anyway, the point is almost moot. However, I'm using Valvoline VR1 20/50 - said to have enough zinc to protect the tappets. I did the proper break-in procedure, which some say trumps a lot of the hype about zinc anyway, so whatever the case, I feel I'm safe. As I said, the car doesn't get that much use, and will probably outlive me!
There are plenty of articles in cyberland to read up on - some of which corroborate; others don't. Bottom line is: do your own research, and then make your own informed decision.