I have to say, each car is different and each owner is different in what are his expectations? In my case I wanted a nice car but not by any means a "restoration" or show car or anything like that. I wanted to get it out and DRIVE IT.
Anyway, I sand blasted each bolt head and then stuck them thru holes in a cardboard box to hold them while I sprayed them with a satin charcoal color Rustolium color and put the darn car together.
That worked out well and met my expectations.
If you really want to zinc plat them I would find a place that does such work and drop them off a bucket of bolts. I have done that in the past when the expectations were higher.