It might do it, but I would look at a 750w psu myself to push two of those cards.
Here's a build that's in your budget that I posted on here earlier today that you might want to look at.
This build down below gives you a decent mobo, decent case w/3.0 usb ports, after market h/s (thermal paste included, Windows 7, and a chance to add another one of those factory o/c gtx 560's later on for SLI.
I will be making a VERY similar build to the one he posted... One differnce is I will be using G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 $75 for the ram giving me twice as much ram for only $35 more. Games are starting to need more and more ram... Unless you want to upgrade soon I would just get the 8gig kit instead of 4gig.
I would however go with a 2GB version of the HD 6950 and try to unlock it to a 6970, then you will need a 750w PSU.
The i5-2500k is a far superior processor to the current AMD lineup. Bulldozer is an unknown at this time and no one is even sure these AM3+ boards will run it when it does come out... its all just theory.