Hey guys, i'm looking to put together a nice setup and psu is now the question. SLI will be a future investment so headroom is needed. Calculated power requirement for the sli came to 660 watts for the machine. I'm left to decide between Ultra / X-Pro / 750-Watt / ATX for 199.99 and the OCZ / GameXStream / 700-Watt / ATX. for 179.99. Which would be better quality or best choice to go with?