I disagree, Cooler Master is a decent brand. That GX 650 has 52A on the 12V, and 25A each on 3.3V and 5V. This should be sufficient.
A Corsair 650TX is rated nearly the same, 52A on 12V, 24A on 3V, 30A on 5V.
As for GPUs, either the 6870 or 6950 are going to give "mid to high" graphics for the next few years. I'd say go with the 6950 because you might be able to BIOS flash it to a 6970, if you're willing to take the risk. However, either way if you're at 1080p gaming they should be adequete. Right now you wouldn't be able to max out Crysis or Metro 2033 but nearly all other games would be on high or better.
I also think a 6870 is slightly better value if you consider crossfire in the future as two of them will perform really really well.
The only other consideration is whether you might upgrade to eyefinity, ie: 3 monitors. For those super high resolutions the 6950 would be better due to having 2gb VRAM.
You might also want to look at a 560 Ti or 470 from Nvidia.