Sorry for the delay, got part way through, then called away.
Thanks terry1966 for stepping in.
I hope you understand that my comments and suggestions are to give better performance and are in no way a criticism of your capabilities.
A link to the Corsair PSU models, > http://www.corsair.c...er-supply-units
The i7 is the right choice if you are planning video/photo/ editing.
CPU cooler. FYI. Where a CPU is supplied with a stock cooler, this from both Intel and AMD, and you choose to use a different one, you will void the 3 year warranty, should damage occur you will not have a legit claim. The stock cooler will keep the CPU within it's thermal limits, providing you are not overclocking. I always advice using the stock cooler first and if it does not perform as you require, then change it.
RAM, Stick with the Default 1600MHz, going higher gets minimal performance gains and causes more heat. Also consider using low profile sticks, should you decide on a aftermarket cooler later, memory with high heat spreaders will severely limit you choice and orientation of the fan/s. I use the G.Skill Aires series.
HDD. Using a large single drive for the OS and Data can cause you problems later if the drive gets corrupted or fails or you need to reinstall the OS. Consider using a SSD for the OS and programs, a mechanical drive for Data storage and ideally an external encloser for backups.
The build would be SLI capable. Before going that route, please do more research, single vs duel GPU, especially when using a single high end card. I think the disadvantages rule it out for me.
I read online that a 750 watt should do it for 2 gigabyte 970s
That would depend on the total power requirement of the whole system. More important is the available Amps on the 12 volt rails/s and the PCI.E plugs required by the GPU/s.
Push vs Pull, With regards to case cooling seems to be just a personnel choice, there appears little difference in performance. I concentrate on a good uninterrupted air flow. It is harder to maintain a constant positive pressure in a case, as soon as heat rises and more exhaust is used, the intake fans must synchronize to keep the balance.
On this site, clicking the country, top right, will give alternative prices. Unable to find you selected MB.
a build for your consideration. > http://pcpartpicker.com/p/C9F7ZL