EPS12V - 24 pin power supply

I have a new ASUS motherboard that has an EPS12V 24 pin power connector on it. While it will work with a standard 20 pin ATX power supply, I prefer to provide the power the motherboard is designed to have. It is my understanding that the additional 4 pins feed extra voltage to the PCI express bus -- which, concidently, I'm having issues with my PCI express video card.

A few questions:

1. What is the best brand of power supply in the 500 to 550 watt range that will support the new 24 pin connector? I know Antec makes one.
2. I can get a $9 adapter to convert a standard ATX 20 pin connector to the requisite 24 pin connector. Is it wise to use one of these?
3. Regarding the power supplies that come with the 24 pin connector, is there really a design change or are they simply installing the 24 pin adapter internally?
4. Does someone already have an adapter that would be willing to send me a pinout diagram? I have connectors in my garage and can modify my existing ATX power supply.

Thanks.