Can a Antec EA650 650W PSU take 4870s in crossfire, or 260s in SLi?
And while I am at it can the CORSAIR CMPSU-750TX 750W take 4870x2 in crossfire or 280s in SLi?
Both PSUs will be able to do it easily. If the Antec doesn't have enough connectors, just use some molex to 6 or 8-pin PCI-E adapters and you'll be fine.