The Crappermaster PSU is not good. The similar GX650 was summarized by HardOCP as a "polished turd in a box" (this isn't my usual anti-Crappermaster spiel about their dishonesty; this unit is not up to minimum quality standards, and should be avoided).
Disclaimer: Over the last three years, with one exception, I have built only AMD systems.
Now then... Based on a series of recent benchmarking articles here at Tom's, there is no longer a price point at which Intel is not the superior choice. Unless you already have the CPU and/or motherboard, your best option will be an Intel build.
Use the sticky in the New Build forum here: http://www.tomshardware.com/forum/261222-31-build-advic... which asks all the questions we'll need on such topics as intended uses and budget.
There are two versions of the Cooler Master GX 750W. The original one with the model number RS-750-ACAA-E3, which is built by Seventeam and has received multiple negative reviews.
The second one has the model number RS-750-ACAA-D3 and is built by Enhance, it is broadly an improvement over the Seventeam built one, but it hasn't been reviewed at the same sites which gave the thumbs down to the original one, plus the review it received at Xbitlabs has put me off it. Also I've rarely seen that model when looking at websites which sell it.
So bottomline I would try to get something else as either way the GX 750 is not the best option.
You don't even need as much as 750W PSU to run a system with two 6870s, let a single one.