What hard disk for Nas?

Hello all. I wondering if someone have some new hard disk for NAS minimum 4TB IronWolf example with 100$
but i wondering what is better fast hdd 5400 rpm 7200rpm or a cache 64mb or 256mb. In this case what is better faster hard disk or cache?
Have you got another experience with hard disk?
I know they are diffrents a colour hard disk black,green,red,yellow,green.
Example on my PC I have WD RED a colour for a example server hard disk. Have you another experience with some another model hard disk NAS or for personal use home pc?