More info dude, what speeds are all these drives going to be at? What CPU and motherboard? Also, output is only one factor to take into cosideration when buying a PSU, you need to figure out what rails you need, and what current they need on 'em.
Intel C2D E6320 / AMD Athlon X2 3800+
Gigabyte 965P DS3 / DFI nF4 Ultra-D
2GB OCZ Gold PC2-6400 / 2GB OCZ Gold PC4000
eVGA 8800GTS 320MB / eVGA 6800GS 256MB
150GB Raptor / 74GB Raptor
2x500GB / 320GB
OCZ GameXStreme 850w / OCZ StealthXStream 600w