How far are you looking to overclock your cpu? 4.5-4.8ghz can be achieved on air with something like a hyper 212+ or a Xigmatek Dark knight/red scorpion and such which are around the $30 mark...
I wouldn't cheap out on a mobo and go something like this UD4
, 12+2 power phases, the option of SLI/CFX with upto 3slot cards in the future should you see yourself doing that, and considering your CPU is a 2500k then it will definately handle 2 cards...
In a years time you could pick up another 6970 for cheap and then you will be laughing
I'd go with this PSU
as it is 100w higher rated and $10 cheaper and same 80+ bronze rated