$339.99 for those two, and a XFX PV-T71G-UCF7 Geforce 7900GT 256mb for $234.99,
It is a very good buy; I was just noticing it earlier today. I'd get an eVGA 7900GT because of the step-up program.
What about this case and power supply...
is 400w going to be enough to power all of the equipment?
Maybe. What are the amps on the 12V rail? The 12V rail powers the motherboard, CPU, grahics card, hard drives, and some other stuff. Wattage is equal to amps times volts. So if the 12V rail has 20 amps, you multiply 12*20, and get 240 watts which is shared by all those components.