Get the 6770 rather than the 6670 (5670 = 6670, 5770 = 6770 , AMD rebranded everything AMD when they went to the 6XXX series cards. Many of them are the exact same model as the 5XXX counterparts, just with the AMD logo and an increased first number.). The extra ~$20 or so you spend gives you a very nice boost in performance. I'm rocking a brand new build with a 6770 as the GPU, and I've been playing every game I own at maxed settings with no issues. It's not at 1080p just due to the crappier monitors I've got available, but it looks fantastic just the same.
It doesn't hurt getting a better PSU than you need now, as you can always get better hardware in the future that will require the better PSU. I've got a 700W version of that OCZ PSU you posted, and it's ~300W more than I need. But, if I upgrade to Crossfire graphics in a year or so, I'll need the better PSU.
Hope all goes well, sounds like you're going to really enjoy the build
. Just be sure to get a nice heatsink/fan for the CPU. $30 seems to be a good price point for a quiet + efficient combo,
this is favored by many builders, while
this is what I ended up getting. It's doing great on my Phenom II X4 955 BE, though I've still yet to get some nice thermal compound on it. It's dead silent too, honestly something I wasn't expecting.