Yeah, 1gb should be fine, unless you're doing some serious AA/Multi-monitor then you'll probably need 2Gb, but otherwise, 1gb will work fine for 1080P.
Get a cheap PSU, but not a crap one, get one that's well reputed, like OCZ, I hear they have really great budget models, also Antec and Corsair to name a few.
Also, you might want to buy some of your own thermal compound, such as MX-4 for your i7, since the new IVB CPUs come with crap thermal compound on the stock heatsink, causing higher temps.
Edit: Misread the graphics cards; I agree with crowe, you should probably focus on getting a higher-end graphics card. The ones you listed will probably struggle to play modern games, I suggest a 7850. From what I've heard, those in crossfire are really great.