The CORSAIR CMPSU-750TX 750W is an excellent power supply. I build pc's for other people. For the past several years I have been using Corsair exclusively. The psu's are very stable and reliable.
You also might want to look at PC Power & Cooling, Seasonic, and Thermaltake psu's.
drobb2626 is correct. It is possible to use an adapter cable in place of the 6 pin, 2x3, PCIe cable. The adapter cables are available from many on line vendors.
There have been posts made by other people indicating a top quality 600 to 650 watt psu can power two 4870 video cards in Crossfire mode without any problem.