How much power do i need?

[Cheesetogo]

I would suggest against modular, as they tend to be overpriced and less powerful than comparable regular psus. I would suggest the OCZ 520 watt powerstream or the Enermax 535 watt. Both are excellent psu's that will power your system well. I would not suggest spending more than ~150 on a psu. 600 watts is not necessary.