what is the best graphics i can get for Pci-e x16

The card has one 6-pin PCI Express power connector located near the end of the card and Sapphire recommend a 500W or greater power supply with one 75W 6-pin power connector. The entire platform with the Sapphire Dual-X R7 265 OC installed was consuming 113 Watts at idle and hit a maximum of 284 Watts when gaming. http://www.legitreviews.com/amd-radeon-r7-265-2gb-video-card-review-with-sapphire-dual-x-r7-265_135733
I would be very concerned using the stock PSU with this, it likely does not have a 6-pin connector and using pigtails is just asking for trouble.