That kit has everything you need to get the system up and running. But you might want to think about picking the components yourself. The price for the kit is only good, in my opinion, because the price of HDDs is so high due to flooding (ie. a Samsung F4 2TB is going for $219, it was $80 about a month ago).
What will be the primary use of the machine?: (ie. productivity, gaming, etc)
Additional Comments: I'm trying the keep the full purchase under $400, and the link I have above seemed to have everything I need. I don't need a hard drive that big, so that may be a place to cut down on what I'm spending