For a smooth finish, you're going to want the kit. By the time you buy all individual chemicals, you'll easily spend a couple of hundred dollars, and you won't have any of the things you need to control the plating to get a smooth surface.
As I recall from my kid's book of science, written in the 1960's, when a child's safety was clearly the last thing on the author's mind, non-conductive items you wanted to electroplate were first painted with a conductive paint containing graphite, and other components I don't recall. But that was just a game really, if the surface wasn't mirror smooth we didn't care, we just got to see electroplating in action.