If you aren't going to do SSD caching you can go with a P67 motherboard. The only real difference is support for Intel SSD caching.
You probably want to get a higher capacity PSU. You're fine with that PSU for a 6770 but in the future you might want a more powerful card and it is a pain to have to tear out a PSU and replace it every time you want a new graphics card. Get a 550w or 650w and then if the money starts rolling in you can upgrade your graphics. This assumes you are planning to game at a decent resolution.
You will also want a CPU cooler for overclocking. Reportedly, the boxed cooler is actually pretty good, but you can do a lot better.
Why would you get an i5 2500k with a 6770? That would be a rather large bottleneck.
I'd dumb down the processor to something like a i5-2400 or 2300, or maybe even an i3-2100, then get a graphics card like a 6850 or 6870.
Here's a good one. MSI HD6850 Cyclone
And a i3-2100 would actually be just fine, it's a great chip, beats out AMD quad and 6 cores pretty commonly.
I'd also get a larger power supply, here's a quality one with good amps on the 12v rail.
If it is what your budget recommend, I would get a I3 2100 or an AMD 960T CPU, a cheaper motherboard, and a faster video card. Your movies won't play slower, nor your music, but your game should play better than with the 6770.