2nd build looks ok but consider this:
This Seasonic 620w is $78.99 (nearly $50 off!!!)
SeaSonic M12II 620 Bronze 620W ATX12V V2.3 / EPS 1...
* I have the Antec version of this model and it runs very well
If you go with a 7870 you can save about $60-80 and their performance is very close to a 7950 (5-10% @ stock and nearly zero difference if the 7870 has a mild overclock)
If you go with AMD then consider the 970 series boards (Gigabyte UD3, ASUS Evo models for example). They have nearly the same features (except SLI in most cases) and are much cheaper. Spend the savings on an FX-6300 and a Xigmatek Gaia cooler if you want some more oomph from the setup.
