Kool, what is the price of that 770? FYI the new 970 are out today and some of them are as inexpensive as 330$, even less if you look around, I've heard of one of the eVGA models going for 329$. This may be less than the 770 you've picked, I'm almost sure of it, and will be more powerful to boot, I'd look into it in your shoes.
See! Like I said in the first post I made here, if you waited just a couple weeks, as you did, you not only have saved $, but will gain a HUGE performance leap to boot, as I just checked that Windforce 770 and the best price on NewEgg was still 349$, and there are many 970 cards including eVGA (my personal favorite) for less than that. Save 20$, get much faster card. Well worth the wait IMO, good on you.
Also, regarding your PSU question and concern, the new 970 cards are even more power efficient than earlier cards, you'll be fine with that PSU you've selected, no problem.
IMO your system now, especially with a 970 GTX card, will last you a long, long time, in terms of keeping up with current and upcoming games. Overclock that CPU to even it's mid level and very safe potential, and same with the 970, and it'll put up some pretty impressive numbers considering the cost of what, 1100$ ish? Very cool IMO. Plus it'll look cool with one of the better cases (I have 2 myself), and be easy to move around with the big springloaded rubber handles on top.