600 would do you better, but the higher you can go the better you can make it.
Since it's a computer you'll likely be using in the next 5 years, you won't want to skimp on the amount you put up front for it.
That is unless you don't have a job, then you'll be in the same boat I was.
What I did was buy good parts over time starting with the motherboard so I could upgrade all the other parts with ease as the motherboard has to be good to take better hardware. It took a while but it turned out pretty good after a good year of saving up.