The min psu requirement is 500w so you should be fine. It is also recommended that you have 36A on the 12v rail, so if you have more than one 12v rail you can add them up and hopefully reach 36A. My card just came in the mail and while I haven't gotten to install it yet in my Cooler Master, I sure hope it fits. The card is friggen massive compared to my 6800gt so here's hoping. I'm sure I will have to rearrange my hd's. You may want to check the rebate center on newegg for a better deal. I got my evga superclocked card for 279.99 a week ago.
That would get you the SC for the same as the standard.