Noob who needs help picking power supply

Here's the deal. I am building my first PC because I was inspired by the $1300 enthusiast build. So far I got this:

Processor: Core i7-920
Motherboard: EVGA’s X58 3X SLI
Graphic card: Either Radeon HD4870 in crossfire or GeForce GTX 260 in SLI...dunno for sure yet.
RAM: G.SKILL 6GB triple-channel kit
Hard drive/s: Caviar Black 1TB

From what I have read the GTX 260 in SLI will require a 700watt PSU-
http://www.guru3d.com/article/geforce-gtx-260-review/4

And the same goes for the Radeon HD4870 in crossfire...a 700 watt PSU-http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/9159-ati-hd4870-hd4850-crossfire-performance-review-15.html

So I guess I need a 700 watt power supply that can give 50 amps on 12 volt rails. Am I right? If so... what should I get?

O yeah thats important. I'm using the enthusiast build as a rough guide. And since they spent $120 I guess I'll be in that ball park too. But If I go over a $100 on the final project then thats not TOO big of a deal. I also have a saving of $100 if I go with the Radeon HD4870 graphic cards(this is y I haven't decided on cards yet. The savings might be needed to cover other costs). So splurging for quality won't hurt the pocketbook extensively.

PC Power & Cooling S75QB

CORSAIR CMPSU-750TX

Antec TruePower New TP-750

The Corsair 750TX looks like an excellent option. But then again so does the PC Power & Cooling S75QB. So which of the two should I get? They look identical to me. From what I have read they both have 5 year limted warranties(someone check and make sure I am right), offer the same power/amperage, and have great reviews. Is this a win-win situation or does one of them really stand out?

Corsair is slightly quieter under load
PCP&C has slightly better output
It's a win-win situation.