Chains -- I'm not aware of anything in the same league as Izumi V (except for the old Regina CX which hasn't been made in more than a decade) -- and that includes the lesser Izumi chains. All the track chains last well enough, as far as I can tell, and they're all plenty strong. It's just that the top line Izumi sounds and feels much, much better than anything else, in my experience. The KMC chains are noisy and often feel "crunchy" underfoot. So if feel and noise are important to you, the Izumi V is the way to go and, with care, should last a very long time. If feel and noise are not important to you, any old thing will work.

Cogs -- Suntour, Shimano, and Campy all make/made very good cogs. EAI/Euro-Asia is a step down, at least in their "standard" line. Their "Superstar" cogs are exceptional, however.

Chainrings -- need to be straight and true and beyond that I've never found a bad one. IOW, if it's straight it's good and if it's not it's bad. Nothing else makes a difference, in my experience.

In my world, "perfect" is an Izumi V, a Superstar cog, a true chainring, and an absolutely straight chainline -- down to the millimeter. As long as it's clean and lubricated -- not with some White Lightning kind of crap, but with actual wet lube -- and the chain tensioned correctly, you will be happy.