Both companies have solid reputation, so I don't think you can go wrong with either of them.
However, they each have more than one 760 models, depends which ones you were looking at precisely. Personally, I prefer designs with dual-fans. They run quieter & cooler. Only drawback is that they reject part of the hot air inside the case, but that's not a problem at all if you have good airflow in your case.
forgot about the different types haha i was looking at the msi twin frozr and the evga super clock with the acx cooler both 2gb versions. i also have the fractal design r2 planning on filling all 6 air slots. is it better to have postive or negative airflow? there are people who prefer one or the other